Chapter 1: Forensic Science Free

Forensic science is a fascinating subject, the science is serious but the term ‘forensic’ seems to give it a ‘sexy’ appeal. Forensic science practitioners (henceforth collectively referred to as forensic scientists within this book) soon discover when talking to the general public that many people have very high expectations of forensic science and what it can provide to an investigation and a court of law. This is mainly because of their fascination with the subject, often alluded to as the ‘CSI effect’, which may be a consequence of the proliferation of TV dramas such as CSI on the subject of crime scene investigation and forensic practices typically covering scene and laboratory investigations, digital technology, pathology and many other related subjects. The material in this chapter sets out to address these high expectations, by providing an explanation and understanding of forensic science, a discussion of its origins and how forensic science services (frequently referred to as forensic practice) have been developed over the years, and how it now operates in the United Kingdom (UK) within a broader international setting. The duties of the forensic scientist and how the required high standards of analysis, reporting and behaviour are obtained, maintained and delivered also form important aspects of this chapter.

If one were to ask one hundred forensic scientists to define forensic science it is possible that one would receive one hundred different definitions, but it might be expected that among these the terms ‘science’ and ‘legal process’ or ‘law’ would dominate. This would rightly refer to their work at a scene or in a specialist unit or facility, such as a laboratory within the criminal justice system (CJS). Therefore, a high-level working definition is ‘forensic science is science used for the purpose of the law’. Consequently, any subject or topic carried out using a scientific method for the resolution of legal disputes is considered forensic science. This broad definition covers criminal prosecutions in the widest sense including consumer and environmental protection, health and safety at work, and civil proceedings such as breach of contract and negligence. It also covers crime against both humans and non-humans, although the focus is often on the former. When the first UK Home Office Forensic Science Regulator (FSR) was appointed in 2008 the definition was reviewed and defined as “forensic science is any scientific and technical knowledge that is applied to the investigation of a crime and the evaluation of evidence to assist courts in resolving questions of fact in court”. The current FSR, in his foreword for the 2022 Quality Assurance Agency (QAA) Benchmark statement for forensic science explained forensic science as “a critical part of the investigation of crime and the administration of justice, not only to identify offenders and provide expert evidence to the courts but it is one of the strongest safeguards against false allegation and wrongful conviction.” However, the application and delivery of forensic science is always changing such that the term ‘forensic practice’, ‘forensic science practice’ and ‘forensic science activities’ are now being applied more widely to the use of science in the investigation of crime by the police and by the courts as evidence in resolving an issue in any subsequent trial. This practice will therefore typically require an individual or individuals to be apprehended as those responsible for the incident. Consequently, the definitions of forensic science will adapt to the times but still have the foundation of operating within a legal framework. During 2015 the Chief Scientist, Sir Mark Walport, published his second annual report entitled Forensic Science and beyond: Authenticity, Provenance and Assurance. Interestingly, this report attempted to set forensic science in a much wider context rather than the traditional definition of the application of science within a legal framework.

This widening of the definition follows a general trend. In 2022 the Sydney declaration delivered a new definition, which interestingly excludes any specific reference to the word ‘forensic’ (relating to courts of law) and provides seven supporting principles for forensic science. Instead, forensic science is defined as a case-based (or multi case-based) research-orientated endeavour using the principles of science to study and understand traces – the remnants of past activities (such as an individuals’ presence and actions) – through their detection, recognition, examination and interpretation to understand anomalous events of public interest e.g. crimes, litigations, security incidents). Regardless of the exact definition, the practice of forensic science will continue to evolve as part of some form of investigation to support justice.

The term ‘forensic scientist’ however is generally accepted as meaning someone who works in a laboratory or specialist facility carrying out examinations on various materials who ultimately can appear as an expert witness in a court of law. These materials typically being those recovered from a crime scene (a physical location or individual for example), or something relating to an investigation. The forensic scientist can also be someone who attends crime scenes as a specialist, often in more difficult and high profile cases, as part of a team of forensic practitioners. The term ‘forensic practitioner’ is therefore used as an alternative to forensic scientist and may be considered a more inclusive term to encompass all those involved within the investigative process from the crime scene to the court room.

Regardless of terminology, all those involved in the investigative process in England and Wales within the legal framework are subject to the Criminal Procedural Rules (CPR) and specifically Parts 19, 31 and 33 of those rules (these rules are also broadly adopted in Scotland and Northern Ireland by forensic scientists). The CPR and obligations of those who may ultimately be involved in disclosing and giving written or oral evidence in a court of law are covered in more detail in subsequent chapters. Those governed by the CPR include crime scene examiners, digital forensic examiners, fingerprint officers, and others as core within the investigative process, remembering that there are other equally important specialisms and experts available to advise investigators and courts such as forensic medical examiners, custody retention officers, etc. With the advance of digital technologies, those investigating the specialised area of ‘digital forensics and cybercrime’ are an ever-growing expertise. In recognition of the growing digital/cyber area the UK Government delivered the National Cyber Security Strategy 2016–2021. As a result of this strategy the UK Cyber Security Council (CSC) was created as an umbrella body for existing professional organisations in support of the challenges of cyber security and in 2021 the CSC was granted charitable status.

In the mind of the public, confusion can also exist between forensic scientists and those involved in forensic medicine (the latter sometimes being referred to as legal medicine). The forensic scientist, as defined above, can be involved in all types of criminal investigation but forensic medics in general restrict their activities to criminal and civil cases where a human body is involved. These are nearly always serious cases such as murder or rape and other sexual acts, and will require the participation of pathologists, police surgeons, forensic medical examiners or Sexual Assault Referral Centres (SARCs).

Although the term forensic practitioner seems to be more acceptable for the courts, more specific terms are still used and often preferred within the forensic science community. This lends itself to a much wider definition of forensic practice to incorporate the recovery, examination, and analysis of materials as well as incorporating the various technological changes all within the court environment. This was reflected in the previous definitions given by the FSR and others. However, the narrower definition is implied in the title of this book and the following chapters, which discuss the use of science in the investigation of offences against organisations, the individual and property including cyber-attacks, murder, violent assault, robbery, arson, breaking and entering, fraud, motoring offences, illicit drugs, poisoning, etc. This chapter will not attempt to resolve the ongoing debate of whether forensic science is a science, an art, both or neither and this chapter will not cover the probative value of contact trace materials such as fingerprints, footwear, tool marks or physical fits in the context of establishing a common source.

The origins of forensic science can be traced back to the 6th century, with legal medicine being practiced by the Chinese. During the next ten centuries, advances in both medical and scientific knowledge contributed to a considerable increase in the use of medical evidence in courts. Other types of scientific evidence did not start to evolve until the 18th and 19th centuries, a period during which much of our modern-day knowledge of chemistry was just starting to be developed. Toxicology, the study of poisons, emerged as one of the new forensic disciplines, and was highlighted by the work of Orfila in 1840 with his investigation into the death of a Frenchman, Monsieur Lafarge. Following examination of the internal organs from the exhumed body, Orfila testified on the basis of chemical tests that these contained arsenic, which was not a contamination from his laboratory or the cemetery earth. This evidence subsequently resulted in Madame Lafarge being charged with the murder of her husband, but more importantly raised the significant problem of contamination. As our technology advances and deals with smaller and smaller traces, contamination is an ongoing concern for any forensic scientist whether they are recovering, examining, analysing various materials or interpreting their findings. It is highly significant that the oral evidence to the court noted that the arsenic was related to the body and not the surrounding ground or laboratory. This could be argued as a form of quality assurance with an early approach to the evaluation and interpretation of findings with given alternatives i.e. the arsenic found in the body could have come from another source, for example the background level of arsenic in soil.

During the latter part of the 19th century there was also considerable interest in trying to identify a person, which today would be encapsulated within the term biometrics. One approach, studied by Alphonse Bertillon, was to record and compare facial and limb measurements from individuals. This proved to be unsuccessful because of the difficulty of obtaining accurate measurements. However, it was the first recorded attempt in a criminal investigation to use a classification system based on scientific measurement. Interestingly, and in accord with this principle, forensic scientists today use the results from a combination of analytical measurements to discriminate between groups or to compare samples. Hence, modern approaches have resulted in greater success using CCTV, speech recognition and facial recognition. A more successful development in human identification was to come from fingerprint examinations. Although Bertillon is reported to have used fingermarks/latent fingerprints (latent inferring something that cannot easily be seen by the naked eye) from a crime scene to solve a case, it was Sir William Herschel, a British civil servant in India, and Henry Faulds who were credited with performing most of the early investigations. Faulds, a Scottish physician, is also accredited with establishing the fact that fingerprints remain unchanged throughout an individual’s life. However, it was not until 1901 when Sir Edward Henry devised a fingerprint classification scheme for cataloguing and retrieving prints, that the full potential of personal identification through fingerprint evidence could be used in forensic investigations.

The development in the evaluation and comparison of fingerprints is much debated and will no doubt continue. Within the UK, a specific number of points is no longer required for a comparison to result in an identification. This zero-point criteria has placed a greater individual responsibility on fingerprint officers in exercising their evaluation and interpretation. Probably the biggest UK inquiry into fingermark examination and interpretation was as the result of an initial prosecution, which was later over-turned during the Scottish Fingerprint Inquiry, which issued its report in 2011. However, broader inquiries into the scientific validity of forensic science have been undertaken in the United States of America (USA), in 2009 by the National Academy of Sciences and in 2016 by The President’s Council of Advisors on Science and Technology (PCAST). Despite establishing the Organization of Scientific Area Committees for Forensic Science (OSAC) in 2014, who began to address the lack of discipline-specific standards in forensic science, the PCAST report continued to make strong recommendations for strengthening the robustness and validity of feature-comparison disciplines, such as latent fingermarks. Whilst these reports and their recommendations received strong criticism and objection from practicing forensic scientists across the globe, they have resulted in significant research growth, aiming to defend, scientifically underpin and quantify the error associated with the methods used in the pursuit of justice. In addition, research has started to evaluate the consistency and depth of reporting practices within and between forensic disciplines, which has further evidenced the need for change. Examples include articles published in Science & Justice by Bali et al. in 2020 and Sunde in 2021. Most recently (2022), Needham and colleagues demonstrated that fingerprint officers report more consistently when using a prompted approach such as an analysis form. However, forensic scientists and researchers such as Morrison (2022) highlight the need to move towards developing more objective systems that can compare and evaluate forensic evidence using machine learning and sufficiently large, relevant training populations; an example was published by Basu and colleagues in 2022 in the field of forensic firearm examination. The key to evaluation and interpretation being the need to have a balanced approach (with alternative propositions) and considering the likelihood of each of these alternatives to calculate the overall probability for the hypothesis (likelihood ratios).

Body fluid samples have also been found to contain information that can help to identify an individual. The progress made in this area has been dramatic and major advances have occurred within the past thirty years. Now we simply refer to ‘DNA profiling’ to cover the examination and amplification of the DNA from a variety of body fluids and body parts. However, until 1900 it was impossible to determine if a blood sample or stain was of human or animal origin, or to classify human blood into the four main groups: A, B, AB and O or various enzyme systems. These categorisation methods have now been superseded by the ability to differentiate between species and individuals using their DNA. Since the discovery of human DNA fingerprinting in 1985, research into the recovery, extraction and amplification of material to produce a DNA profile has seen massive advances in sensitivity and has had an instrumental impact on how forensic science has been used to support the investigation and prosecution of crime on a global scale. For example, DNA analysis can now differentiate between identical twins and can be used to identify human trafficking routes. Originally enough blood to cover a 2p coin was required to develop a DNA profile, but now DNA can be recovered by swabbing or extracting an area that has no visible staining but is thought to have been ‘touched’ and thus contain trace levels i.e. minute quantities of material. Hence the terms ‘Low template DNA’ and ‘touch DNA’. However, the term ‘trace DNA’ is now deemed more appropriate to imply nano or pico amounts of DNA. As we no longer need to be able to see the (body fluid) stain by eye, it has been increasingly important to explain how that DNA came to be in that location, thereby considering where and when the contact was made and the surrounding circumstances.

In connection with ‘contact’, it is Edmund Locard who is attributed to the important basic overarching principle and succinct phrase, ‘every contact leaves a trace’. Whilst this phrase is well known within the forensic science community, it does not fully encapsulate the detail provided within the relevant passage from his 1920 publication ‘L’enquête criminelle et les methodes scientifique’, which according to Roux and colleagues translates as:

Although the examination of fingermarks or body fluids, which might be present in only trace amounts, may directly implicate an association of particular person with a victim or a crime scene, other types of trace evidence such as glass, paint, fire accelerants, gunshot residues, drugs, fibres, hair, pollen, digital evidence, etc., can provide links that establish contact between objects and/or people involved with a victim or present at a crime scene.

It is interesting that today and noted above, the technology and sensitivity to detect smaller and smaller quantities, often sub-nanogram, does not necessarily implicate an individual but triggers the question as to how the traces of that individual got to where it was recovered from. Further it often raises the questions of secondary and tertiary transfer between people or objects, and even whether transfer could have occurred through the air. The ability to now analyse such a variety of materials stems from technological advances that have occurred particularly in the past thirty years. Many of the analytical techniques that have been devised offer impressive sensitivity and permit examination of minute quantities (traces) of material which cannot be observed directly by the human eye. To provide some indication of the amount of material being examined in these trace samples, think of a grain of sugar. This can be seen without any difficulty and weighs about 1 milligram (1 mg), (i.e. one thousandth of a gram or 1 × 10⁻³ g). Now consider one millionth of this quantity, which is 1 nanogram (1 ng or 1 × 10⁻⁹ g). This amount of sugar cannot be seen, but quantities as small as this can be detected by many analytical techniques. Even lower detection limits (picograms or 1 × 10⁻¹² g) can be obtained routinely with some instrumental methods and techniques. Although this is beneficial, extreme caution is required in the evaluation and interpretation at every stage of any investigation and its subsequent analysis to ensure a result is genuine and not due to contamination or any other artefact. The correct interpretation of a result can then be used to advise the investigator and support the court of law to administer justice. An incorrect result or interpretation may lead to an unresolved case, no conviction or a miscarriage of justice.

Rapid developments in computer technology have also played an important role in the advancement of forensic science and practice. Apart from their use in manufacturing instruments and producing analytical data, computers permit the storage of very large amounts of information that can be searched very quickly. With increased computer capacity has come the establishment of local, national and international databases. For example, DNA (recovered from body fluids and biological materials), fingermarks/prints and footwear marks, etc. The purpose of these databases is to help in the identification of an individual or items associated with an individual as well as supporting the overall evaluation of findings. Databases can save a tremendous amount of time and effort in an investigation and are beneficial both to the police in following their enquiries and to forensic scientists identifying emerging trends and providing evaluative evidence and information to the courts. However welcome databases may be to any investigation, their use needs to be balanced against ethical issues surrounding how the information is gathered and what consents have been provided as well as consideration of individuals’ rights. For example, the retention of DNA profiles of individuals not convicted of a crime was debated in the European court, resulting in a review of how long samples and profiles could be retained on the national DNA database (NDNAD). Other forensic disciplines, such as fingerprints and firearms, also have national databases in the UK and elsewhere, known as IDENT1 (or AFIS outside of the UK) and Integrated Ballistics Identification System (IBIS) respectively. Such databases can facilitate more effective intelligence gathering and the investigation of crime on a potentially global scale.

There are other interesting debates in relation to databases including who creates and owns a database, who contributes, what information is required to be placed within the datasets of the database, who cleans and curates the data, how is data stored and transported and with whom can this information be shared? Further, how useful will the data be to an investigator, evaluator or interpreter of the information? This is particularly a challenge in England and Wales where forensic science provision is currently split between numerous public and private providers, and the forensic science marketplace is extensive and likely unsustainable, making the provision and implementation of national databases in this jurisdiction for areas such as footwear, fibres and drugs very difficult. In addition, access to and usage of data stored by private companies in England and Wales and internationally may create further challenges. This is not necessarily the case in Scotland or Northern Ireland where, in each jurisdiction, there is a single forensic science provider funded by the devolved governments. Concerns have increasingly been raised about the acquisition, use and destruction of biometric data within the CJS including, more recently, the use of genealogy data to support criminal investigations. As a result, in 2018 the Home Office Biometrics Strategy was published and later the Home Office Biometrics and Forensics Ethics Group and Home Office Age Estimation Science Advisory Committee were formed. Similarly, a Biometrics Commissioner was appointed in Scotland following the passing of the Scottish Biometrics Commissioner Act 2020 in which a Code of Practice was created to promote the adoption of appropriate legal and ethical practices relating to biometric data, its use and retention.

As previously mentioned, obvious advances in technology relate to the area of telecommunication. With increasing use of personal computers and digital devices, fixed and mobile, a whole new, ever-growing area of forensic science has emerged, which will be covered in greater detail in subsequent chapters.

Before specialist laboratories were established, police forces in many parts of the world relied on scientific assistance from people who, through their occupations, were able to provide the expertise required. The expertise being established by having a specific detailed knowledge greater than what one would expect a random person to have. Without a centralised system, knowing whom to approach was a problem for investigators. This resulted initially in the creation of formalised institutions which were almost invariably established as parts of universities or hospitals. Over time, these were restricted to examining and providing expertise in a limited number of forensic science disciplines. As a result, police forces took the step of developing their own forensic science laboratories. Europe took the lead in this development, with the first police forensic laboratory being opened in 1910 in Lyons, France. Thereafter, police laboratories appeared in Germany (Dresden, 1915), Austria (Vienna, 1923) and other countries including Holland, Finland and Sweden, with these last three all coming into service in 1925. It was not until 1923 that the Los Angeles Police Department set up its own forensic science laboratory in the USA. The reason for this change was the failure to obtain an indictment in a case as a result of improper handling of evidence before laboratory examination. Many other police departments across America followed this lead, with the FBI (Federal Bureau of Investigation) laboratory opening in 1932. Interestingly, the first police forensic science laboratory in the UK was not established until 1935, when the Metropolitan Police Laboratory sited at Hendon was opened. How this laboratory started is a fascinating history. It all arose from the unofficial efforts of a constable, Cyril Cuthbertson, who was interested in medicine and criminalistics (in the UK this term is usually associated with the examination of physical evidence such as footwear marks, but in the USA it has a much wider meaning and covers most of the activities undertaken in a forensic science laboratory) and became involved in applying scientific tests that helped his police colleagues in their investigations. Following his examination of a document and his attendance at court as a witness, praise for his testimony and skills soon filtered back to Scotland Yard. The Police Commissioner, Lord Trenchard, took a considerable interest in this matter as he could see the benefits of a laboratory dedicated to his police force. As a consequence, over a period of time, he persistently engaged the Home Office over this matter and this eventually paid off. The success of this laboratory resulted in the Home Office sanctioning the development of their own forensic laboratories and a research laboratory, under the banner of the Home Office Forensic Science Service (HOFSS), providing regional laboratories for police forces in all areas of England and Wales. These laboratories were all financed from central and local government funds until 1991 when the HOFSS became The Forensic Science Service (FSS), an executive agency of the Home Office. Executive Agencies were created to try and operate at ‘arm’s length’ from the government with the longer view of being self-financed and separate from government. In 1996 the Metropolitan Police Forensic Science Laboratory in London became part of the FSS.

Wherever possible, facilities were provided locally but the corporate FSS structure allowed the concentration of specialist expertise in particular laboratories so that a comprehensive service was available across England and Wales. Research for the FSS was carried out at one of the Birmingham sites. In 1999, with the introduction of agency status came the ability of the FSS to charge ‘customers’ (primarily but not exclusively the police) for the facilities offered on a contract, case by case, item by item, or hourly rate basis depending on the circumstances. Hence agency status for the FSS permitted the provision of services to any customer in the UK or overseas. These facilities were also available to the defence in criminal cases. Where work was performed for both prosecution and defence the work from each would be conducted at different laboratories and client confidentiality would be maintained. Other agencies which were formerly part of government departments and offered forensic science facilities were the Laboratory of the Government Chemist (LGC), particularly in the area of drugs and documents, and the Defence Science and Technology Laboratory (DSTL), formerly the Defence Evaluation and Research Agency, operating under the Forensic Explosives Laboratory (FEL) in respect of explosives.

With the closure of the FSS in 2012 the primary customer, the police, needed to ensure delivery of scientific evidence across the whole investigative process. This transition was supported by a program called Transforming Forensics which was police led and funded by the Home Office. This support continues through a group called the Forensic Capability Network (FCN), which emerged in 2020. Other significant changes arose from the government’s desire to level the playing field and not have it dominated by any one provider such as the FSS. Additional companies were formed by amalgamation, such as LGC and Forensic Alliance to become LGC Forensics (now Eurofins), or the setting up new larger companies, such as Key Forensic Services Limited and Cellmark, or other smaller companies and sole traders. Consequently, many of the bigger organisations came together in 2013 to form a body called The Association of Forensic Science Providers (AFSP), which aims to be an independent representative body facilitating the effective delivery of justice and promoting public confidence in forensic science (AFSP also had representation from Scotland, Northern Ireland and the Republic of Ireland forensic science laboratories). In addition, the number of non-commercial police in-house services began to rise. These major changes resulted in a competitive market for the provision of scientific services to the police and the justice system in England and Wales where the provision of services being contracted by means of a rather complex procurement process. Interestingly, England and Wales is often referred to as having a fully commercial forensic science provision. However, the interpretation and significance of this depends on one’s definition of forensic science and its practice.

There are also hidden dangers in a totally ‘privatised’ forensic science service. For example, it could be argued that commercial pressures and competition could lead to compromised standards. Constraints on budgets could also restrict the amount of work requested, the material submitted, the analytical work to be performed and the timeliness of reporting results, not to mention how research is funded in a relatively immature market. Research and development is the life blood of any developing industry and is particularly important within forensic science to keep at the cutting edge and in front of the perpetrators of crime. The danger with this scenario is that these restrictions could prevent the forensic scientist from providing ‘best evidence’ based on a holistic approach to the investigation and reach a conclusion, which might either provide a court with stronger evidence to support a prosecution, or equally show that the accused could not have perpetrated a criminal act. Therefore, it is essential that these dangers are identified and appropriate controls are put into place. The key overriding philosophy is to provide scientific services from reliable witnesses, which subsequently provides assurance to the justice system and confidence to the public. The significance here from the courts’ perspective being the word ‘reliable’. Again, this can be followed up with the CPR as noted earlier.

In England and Wales, crime scene investigation, fingerprint recovery and enhancement are primarily undertaken within police forces i.e. public sector. A considerable amount of other forensic examinations, footwear, digital, etc. are also carried out within police forces. The commercial providers supply wide ranging forensic science services including drug analysis and identification, DNA profiling and other areas of criminalistics involving various analytical procedures and contact traces such as glass, fibres, fire investigation, etc. Therefore, considerable debate surrounds the totality of commercialisation of forensic provision within England and Wales – as there remains clearly a public and private sector provision.

It seems inevitable for there to be a continued debate regarding public and private provision of forensic science services in England and Wales. Increasing areas of forensic science work is performed within police forces with the expectation that the other commercial organisations will take up some of the slack. Crime scene and fingerprint/fingermark comparisons, have always been undertaken within the police forces in England and Wales. However, whilst digital forensic units are now commonplace in police forces, numerous private companies also exist. In addition, whilst NABIS (National Ballistics Intelligence Service) was set up as an independent national policing organisation to investigate gun crime in 2008, it is hosted by West Midlands Police in England and collectively funded by all UK police forces and other partner law enforcement agencies. While forensic science provision in England and Wales is largely provided by commercial providers and police forces, there will always be a need for some private input depending on the specific requirements of an investigation, especially for niche areas such as speaker recognition, microbes and pollen.

Since the demise of the Council for Registration of Forensic Practitioners (CRFP) and the FSS coupled with all the changes within public, private, learned society and professional bodies, there has never been a clearly communicated strategy for forensic science in England and Wales, while the devolved Nations (Scotland and Northern Ireland) have fared better. In England and Wales, this lack of an overarching strategy and vision hampers the totally integrated investigative process from scene to court. In 2015, the Home Office delivered its strategy for forensic science, in which it referred to a national approach to forensic science delivery in the criminal justice sector. However, in 2019 the House of Lords Science and Technology Committee published its review of forensic science in England and Wales which continued to voice concerns for the sustainability of forensic science in this jurisdiction. Following this review, the FCN was established in 2020 to provide national support for forensic science activities taking place within police forces in England and Wales. Although the government issued its digital forensic strategy in 2020, the Government’s Response to the House of Lords Science and Technology Committee’s report on forensic science in 2021 continued to acknowledge that more needed to be done in England and Wales to support the sustainability and viability of forensic science provision. Supporting this endeavour in England is the work provided by the Forensic Science Data Laboratory and the Aston Institute for Forensic Linguistics, which were established in 2019 with grant funding from UK Research and Innovation (UKRI) to develop empirically validated methods for evaluating forensic evidence. Therefore, there have been some efforts to increase funding for forensic science activities. In addition, the National Police Chief’s Council appointed its first Police Chief Scientific Advisor, Professor Paul Taylor, who aims to keep UK policing at the forefront of best practice and connect policing to expertise in science and technology.

While there is still a desire and commitment to achieving an integrated approach to forensic science in the UK, the forensic science provision is separately managed within Northern Ireland and Scotland where justice is a devolved responsibility. Differences in their governance and legal systems means their forensic science provisions are currently publicly funded through government agencies. In Northern Ireland similarly, most forensic science services are provided by Forensic Science Northern Ireland (FSNI) with some provided by the Police Service of Northern Ireland (PSNI).

In Scotland, forensic science facilities were originally provided by independent laboratories in Aberdeen, Dundee, Edinburgh, and Glasgow, each associated with, but independent of, specific police forces. In 2007 the Scottish Police Services Authority (SPSA) was created to provide a corporate service to the police forces for Scotland and effectively created one forensic science provision for the country providing a more integrated scientific service to the police. SPSA was replaced, in 2013, by a single agency the Scottish Police Authority (SPA) with responsibilities for Police Scotland and an independent forensic science service. In 2016 the Leverhulme Research Centre for Forensic Science was established in Scotland at the University of Dundee with grant funding from the Leverhulme Trust and with the strategic aim to support the evidence presented in the Courts with robust scientific data.

Although the laboratories and organisations referred to above can generally be regarded as the ‘official’ ones, there are a wide range of practitioners and practices throughout the UK delivering an independent forensic service to clients. These include university departments, public analysts, fire and rescue services, civil investigation companies, large and small practices and individual practitioners, who are collectively referred to as either small and medium enterprises (SME) or sole traders. Although these may undertake prosecution work, they have a particular role in working with lawyers retained by a defendant in a criminal case to explore the strengths and weaknesses of scientific evidence tendered by the prosecution. This may include the laboratory examination of original or new material in a case, but it will usually involve an evaluation of the results obtained by the original scientist(s) and the interpretation offered. The latter may require modification in the light of further information provided by the client or discovered by the retained expert. Funding for such defence examinations is generally sought from the legal aid board, although their resources have been declining over recent years. Whether a public (e.g. police force or government funded forensic science provider) or commercial organisation, all those practicing forensic science should be seeking appropriate internationally recognised validation of their quality control and management practices. Across the forensic science domain this usually means gaining accreditation of their practices through ISO 17025 (for laboratory practice) and ISO 17020 (for scene practice) accreditation standards, regardless of their size (see Section 1.4).

The introduction of charging for scientific services has therefore meant that private laboratories and other institutions are all competing for custom from the police or in offering a service for the defence. Unfortunately, whilst many of these laboratories had sought quality control and accreditation of their procedures and facilities, there was no recognised system of accreditation or regulation of the forensic science profession in any part of the UK. This meant that any organisation could offer and supply forensic science services whether or not it had the technical competence and experience. This position changed in 2008 with the introduction of a forensic science regulator (FSR) and a tendering process (in England and Wales) for scientific services.

Another historical development in forensic science was the introduction of civilian scene of crimes officers (SOCOs) into police forces. SOCOs (also known as crime scene examiners, (CSE), crime scene investigators (CSI) or forensic investigators) carry out the searching of crime scenes resulting in the collection and packaging of various materials that may provide potential directions for the investigation. Contrary to common belief, it is nowadays quite rare in England and Wales for a forensic laboratory-based scientist to attend a scene (although they attend more regularly in Scotland and Northern Ireland) because the introduction of CSEs into the investigative process was intended to reduce the amount of time forensic scientists were being called away from their laboratory work.

Over the years the importance of CSE/CSI and associated development of forensic strategies at crime scenes together with the need for collection, packaging and transportation of material of potential evidential value has been increasingly recognised. In earlier days this would have been carried out by a detective or a forensic scientist, but it is now usually performed by specialists who have received relevant training in all aspects of crime scene examination including latent fingermarks, evidential traces and recording practices, such as photography. In Scotland and Northern Ireland CSE/CSI training is provided nationally by SPA forensic services and PSNI, respectively. In England and Wales the College of Policing provide a national training programme for delivery by licensed forces; forensic courses are no longer delivered at their national facility at Harperley Hall, Durham. Such professionalism should ensure that the integrity of items received by the forensic scientist for examination will not be disputed. Another consequence of this civilianisation was the introduction of Scientific Support Managers (SSM) to each police force. Their responsibility is to oversee the management of forensic scientific services for the police force in terms of fingermark identification, photography and forensic science work. This has extended to include various technology advances such as laser scanning, digital work and CCTV. The overall role of the SSM depends on the size of the individual police force and, latterly, where various neighbouring police forces have been amalgamated, the individual SSM roles have been replaced with one overall Scientific Support Director or Regional Director.

Over the years there have been various qualifications within the forensic science arena. Via Harperley Hall, the police offered various diplomas and then foundation degrees in crime scene and fingerprints. There were also several diplomas offered by the Forensic Science Society, FSSoc, (now the Chartered Society of Forensic Science (CSFS)). However, these are no longer available.

Academically, the first forensic science qualification in the UK was a Master of Science degree in forensic science provided by the University of Strathclyde in Scotland in 1967. This was followed by a Master of Science in forensic science at Kings College London established in 1985. These qualifications were followed by a wave of undergraduate forensic degrees beginning in around 2000 and master degrees developing around 2004, which unfortunately varied in quality resulting in various critical comments from the practitioner communities. These comments were taken on board by the FSSoc, which developed an educational accreditation scheme to ensure forensic science and academic quality. In this scheme, universities apply against component standards (forensic science, forensic investigation, anthropology, archaeology and digital forensics) to achieve either educational accreditation (full undergraduate and postgraduate degrees), recognition (less than full degrees) or endorsement (essentially post-16 education or foundation year).

The UK Quality Code for Higher Education (Quality Code) sets out the expectations and practices that all UK higher education are required to meet. The Quality Assurance Agency for higher education (QAA) sits alongside the Quality Code to help providers develop courses and refine curricula. The QAA have recognised forensic science as a subject in its own right and a benchmark statement on forensic science was produced for undergraduate and postgraduate awards incorporating the CSFS component standards and this statement underwent significant revision in 2022 to reflect the recent changes.

With the changing marketplace for forensic science, the commercialisation and several high profile miscarriages of justice there were calls for greater regulation. The first full-time permanent post of the Forensic Science Regulator (FSR) was created by the UK government in 2008 following a recommendation from the House of Commons Science and Technology Committee. The FSR sits within the Home Office and operates independently to ensure that quality standards apply across all forensic science services to the criminal justice service in England and Wales and are adopted (but are not mandated) by Scotland and Northern Ireland. This involves the setting, maintaining and monitoring of quality standards. Consequently, the FSR makes an important contribution to the continuing development and delivery of forensic science practice to the CJS. This is achieved via compliance with the Regulator’s Code of Practice (often referred to as the code). Initially this compliance was voluntary, but statutory powers for the FSR to enforce scientific quality standards within forensic science have been enacted by government through the Forensic Science Regulator Act 2021.

The FSR is supported by an advisory council and numerous specialist groups, who develop and deliver the standards to the Regulator for ratification. Since 2008 there have been three Regulators; Mr Andrew Rennison (2008–2014), Dr Gill Tully (2014–2021) and Mr Gary Pugh (2021–present). The role to set, maintain and monitor quality standards within the investigative process remains at the heart of the role, although with the number of forensic providers increasing and expanding especially within police forces this makes the FSR role even more critical.

Historically, the forensic science work performed in the UK has for many years been regarded very highly throughout the world for its standards, innovation and integrity. However, the implications of the change in marketplace, number of forensic providers and funding for research has had some impact on its ability to deliver an optimal service in England and Wales specifically. It is vital that sufficient monitoring and review is provided with resulting actions taken where necessary, to continue to preserve the global reputation of forensic science in England and Wales and, more importantly, to ensure that it is not responsible for miscarriages of justice. In 2023, an all party parliamentary group (APPG) Westminster commission was established to investigate forensic science in England and Wales with a specific focus on the risk posed by the current provision in this jurisdiction to contribute to miscarriages of justice, and is expected to report in 2025 or 2026.

As an overview to this section, Table 1.1 details some key dates of change that have taken place within the UK landscape since the early 90s. However, another change worthy of highlighting has been the increased partnership and collaboration between academia, forensic science providers and forensic science units within police forces and industry. While some universities and police forces have worked and/or collaborated together informally for many years the PCAST’s call for greater research underpinning forensic science was a key driver for the formalisation of some of these partnerships. The Staffordshire Forensic Partnership, Lancashire Forensic Science Academy and Forensic Innovation Centre are all good examples. The Leverhulme Research Centre for Forensic Science in Scotland as part of its work, catalysed a partnership between the National Academies of Science (Royal Society and Royal Society of Edinburgh) and the senior judiciary across the UK to develop judicial primers. These are texts written in simple prose developed in partnership between the judiciary, forensic scientists and the academic community to provide concise yet accurate explanations of the science behind forensic evidence together with any limitations when applied in casework. A range of judicial primers are freely available from the Royal Society’s website and include statistics in legal proceedings, collision investigation, forensic DNA analysis, ballistics, forensic gait analysis, forensic anthropology and fire investigation. Such a collaborative approach is world-leading and a pivotal step forward in connecting science and the law. Both the Royal Society and the Royal Society of Edinburgh also now hold regular events for scientists and the judiciary.

A need was also identified to increase UK practitioners’ access to forensic research and in 2020 a proposal was developed by Bolton-King and colleagues to create a new platform to specifically share unpublished (non-peer reviewed) forensic research and journal pre-prints. The collaboration and sharing of forensic science work between academia, forensic science providers and policing has been supported by the FCN for the last few years. With the challenges faced particularly in digital forensics, the FCN have also built upon and expanded the proposed repository and platform, securing Home Office funding in 2023 to explore the commissioning of a new forensic science data service. If launched, this service aims to provide quality-assured and easily accessible data, reports and tools to those working in the sector.

An increase in open access peer reviewed literature across forensic science journals is also providing access to research and data for forensic scientists.

Further to these national efforts, the International Forensic Strategic Alliance (IFSA) established in 2004, supports the connection of the six existing regional forensic science networks and three strategic partners (Interpol, United Nations Office on Drugs and Crime (UNODC) and the Leverhulme Research Centre for Forensic Science), setting minimum required standards for forensic practice on a global level. IFSA also produced a Research and Innovation Position Statement at its meeting in Scotland in 2021, which was leveraged by the European Network of Forensic Science Institutes (ENFSI) to influence Horizon Europe calls and provide funding for forensic science research and innovation across Europe. The IFSA Research and Innovation Position Statement was also used in discussions with UKRI to align funding in the UK to the global direction of travel.

Other significant developments that support the sharing and advancing of forensic science through international collaboration have included:

• Interpol’s Forensic Science Managers Symposium publications of peer review papers summarising relevant research within a range of forensic science areas.

• Establishing the Scientific Advisory Board for the International Criminal Court who provide the Office of the Prosecutor with updates and advice on advances in technology, scientific methods and procedures in forensic science.

• Launching the 2030 Agenda for Sustainable Development and implementing 17 Sustainable Development Goals (SDG), for which the UNODC supports Member States in their efforts to make the world safer from drugs and crime.

• Specifically aligning international research outputs and educational learning outcomes to SDG 16 (Peace, Justice and Strong Institutions) and 4 (Quality Education) within forensic science and wider criminal justice sector.

• Increasing input from forensic scientists to support the humanitarian work provided by charities and non-government organisations such as the International Committee of the Red Cross to ensure the protection and dignified treatment of the dead.

A police officer investigating an incident will seek clarification of four issues:

1. Has a crime been committed?

2. If so, who is responsible?

3. If the responsible person has been traced, is there enough evidence to charge the person and support a prosecution?

4. Is the crime connected with any other previous crimes?

This clarification is seldom the sole responsibility of one officer and the investigation and court trial will reveal the involvement of specialist police officers, civilian staff, lawyers and scientists. Overall, forensic practice can be expected to contribute to the clarification of all four issues. One very important attribute of a forensic scientist is their ability to accept that they work for the court of law and consequently their approach should not be biased. In other words, they are able to consider information from various sources, review it and provide an independent unbiased evaluation and interpretation, i.e. the information evaluated and interpreted has not been subject to cognitive bias (Section 1.6) in particular.

In most cases there may be little doubt that a crime has been committed, but there are a number of occasions when only a scientific examination of items can inform the investigator that this is the case. For example, the alleged possession of an illicit drug will require identification of the seized material. Similarly, to support an offence of driving under the influence of drink or drugs, a blood or breath sample taken from a motorist will require an accurate analysis not only to establish that alcohol or a drug is present, but that any alcohol or drug present exceeds a permitted level. The presence of semen on a vaginal swab from an under-age girl is evidence of illegal sexual activity. Similarly, the demonstration of toxic levels of a poison in tissues removed at post-mortem from a body of an individual believed to have died from natural causes will be a strong indication of a crime or suicide. Doubts as to the authenticity of a document may be resolved by scientific examination and provide evidence of fraud.

If a latent fingermark is developed and recovered from a crime scene and the criminal’s fingerprints are already in a database, the person potentially responsible for that crime may soon be identified. Similarly, the existence of a database of DNA profiles may enable initial identification of an offender who has bled at the scene of violence or who has left other body fluids in a sexual assault. Although specific identification of an offender may not be provided by scientific examination, useful investigative leads can be produced which will enable the investigator to close certain lines of enquiry and follow others potentially leading to a perpetrator.

Irrespective of any support received from the forensic scientist, the usual diligent police investigator often produces a suspect and the investigator will look to the forensic scientist to provide corroborative or exculpatory evidence to enable a charge, or not, to be made, and may assist the court in deciding whether a defendant is guilty or not guilty. The scientific examination will normally be directed towards two aspects:

1. Examination of material left on the victim or at the crime scene which is characteristic of the suspect.

2. Examination of the clothing and property of the suspect for the presence of material characteristic of the victim or the crime scene.

The biological, physical or chemical characteristics of materials found on the victim or at a crime scene can help to confirm the identity of a suspect and/or provide evidence of their involvement or presence at the crime scene. Blood, semen, saliva, fingerprints, hair and teeth are all characteristics of an individual. Finding fibres from clothing or the characteristic pattern of the soles of shoes worn by a suspect may provide evidence of their involvement, as can materials found that may be associated with their particular occupation. The characteristics of a vehicle used in the crime, such as oil drips, tyre marks or tachograph may indicate where the vehicle had been parked or driven over ground near to or at the crime scene. Paint, glass or plastic from the vehicle after a collision may help to identify the particular vehicle and hence the owner who could become a suspect. The characteristic marks that may arise from weapons, tools or other items used in committing a crime, e.g. a knife in a stabbing, a screwdriver used in forcing an entry or a firearm used in a robbery, especially if found on a suspect, could provide further evidence of a suspect’s association with a crime. Botanical evidence such as pollen may provide links between crime scenes and suspects; finally, even insects found on decayed bodies can assist the forensic scientist and the courts. Investigation of mobile phones or other digital related software are common and can help show communications which may have taken place between individuals as well as locating where these devices may have been. Clearly it is very unlikely that all these possibilities will be realised in a single case, but knowing the circumstances surrounding a case and taking into account previous experiences, the forensic scientist should be in a position to exploit their skills to the benefit of the investigator and the courts.

The crime scene could be an individual, a building or an outdoor area. Any search of a building or outdoor area usually yields materials that are characteristic of the particular location, for example:

1. Domestic premises—external and internal painting, external and internal glass, furnishings, crockery and glassware, etc.

2. Commercial premises—as for domestic premises, plus process materials.

3. External scenes such as gardens, waste ground and fields—soil, vegetation and miscellaneous debris.

Where the scene involves a living or deceased victim, biological material and clothing discussed above for the suspect will also apply as will digital devices.

Having established when the service of a forensic scientist might be required, we can now identify their duties as follows:

1. To attend a crime scene (which may be rarely, depending on jurisdiction), examine material collected or submitted to a forensic science laboratory to provide information previously unknown or to corroborate or exclude information already available.

2. To provide the results of any examination in a report that will enable the investigator to identify an offender or corroborate/exclude other evidence in order to facilitate the preparation of a case for presentation to a court.

3. To indicate wherever appropriate, whether there is any association between the marks or materials recovered at the crime scene to those recovered in any previous cases.

4. To present written and/or verbal evidence, based on evaluation and interpretation of their findings within the context of the given case to a court of law to enable it to deliver justice by reaching an appropriate decision as to guilt or otherwise of a defendant.

Under the adversarial system of trial used in the UK, USA and many other parts of the world the individual forensic scientists may be regarded as, and claimed to be, an independent witness for the court. However, they may not always be regarded in this way by the courts and public. It is therefore essential for forensic scientists to be able to demonstrate competence, impartiality and integrity by attention to issues such as the following:

1. Forensic scientists should only give evidence on work carried out personally or under their direct supervision and within their area(s) of subject expertise. Although, one of the privileges bestowed on an expert witness is that they can interpret factual evidence given by another witness under oath or affirmation in the light of scientific findings and knowledge.

2. Where scientific examinations are relied on for legal purposes, the methods used should be based on established and accepted scientific principles, validated and, preferably, published in reputable peer reviewed scientific literature, so that they can be scrutinised by the scientific community at large.

Where the scientific findings require interpretation, the basis of any interpretation should be available to the scientific community.

It is important to recognise that the responsibilities of individual forensic scientists are personal and not corporate. Thus, in giving evidence they are completely and solely responsible for their own experimental results and for the facts and opinions expressed. However, the corporate environment should be a supportive structure providing appropriate training and continual professional development, standardised methods and procedures, evaluation of performance and a quality management system (QMS). Attention to the latter can be a real source of assurance to the individual forensic scientist, the CJS and the public at large. Further, given the corporate environment mentioned above it is critical that the forensic scientists are also empowered to innovate and be creative in order to adapt to changing trace materials and technology.

There are many definitions of quality, but for our purposes, within forensic science, the International Organization for Standardisation (ISO) is appropriate which defines quality as the ‘degree to which a set of inherent characteristics fulfils a requirement’ (modified from ISO 9000:2015, 3.6.2 in ISO 21043-1:2018).

The ISO 17025 standard was adapted specifically to give guidance to forensic laboratories on both quality management and the technical requirements for the practices and procedures in operation. This standard can be considered the technical complement to ISO 9000. As a result, any organisation that satisfies the requirements of ISO 17025 will also meet the intent of ISO 9000 requirements; the reverse is not true, however. The ultimate ‘customer’ to be satisfied is the court, and it would expect there to be a total QMS in place that will ensure the integrity of material examined by the scientist, the examination carried out and the reliability of any scientific evidence presented. It is expected that the 17025 standard will primarily cover the laboratory work. However, the investigative process is not restricted to the laboratory and the scene is equally and arguably more important. The relevant ISO standard here is 17020. These standards focus on the procedures and standards at the scene and within the laboratory as outlined later (Section 1.5) and dates for their implementation in England and Wales have been established by the FSR. A parallel argument exists alongside these standards, which are those of the individual practitioner’s competency and professional judgement. Many argue that these latter standards are incorporated within the ISO standards, but the question still arises as to how the individual becomes competent with the ability to make professional judgements (Section 1.6).

The quality control system must clearly extend outside the forensic science laboratory environment and places a responsibility on everyone involved in an investigation to maintain a ‘chain of custody’, from crime scene to court. It is also argued that the standard starts upon initial reporting of the incident. In fact, in terms of the materials used to ‘bag and tag’ items it is equally important that they have been produced under a QMS to ensure the quality—particularly with items which may contain minute quantities of trace material such as DNA—hence the term ‘DNA free’ recovery items (e.g. swabs) and packaging. A more appropriate expression would be ‘chain of integrity’, since the court will need to know not only the identity of the links in the chain but also their behaviour, as illustrated in Table 1.2.

Even with this brief consideration it can be noted that apart from knowing the identity of the ‘custodians’ of items at each stage, the court will need to be assured of their awareness of the consequences of any deficiency in the processes in which they are involved. For this reason, in many investigations most of the process is conducted by specialist personnel with occasional assistance from laboratory-based forensic scientists. Everyone involved needs to protect the items from the twin problems of deterioration and contamination. The latter is vital when a suspect has been arrested, since all possible contact between items from two sources must be prevented with proof that the appropriate actions have been taken.

Clearly, if the integrity of the articles received by the laboratory, either as a commercial forensic science laboratory or an in-house police scientific laboratory, has been maintained, the responsibility is then transferred to the forensic scientist. The methods used for the examination of various evidential materials are detailed in subsequent chapters, but certain principles apply to all examinations:

1. Prevention of contamination is a prime requirement, particularly as such small amounts of material can be examined and characterised. The practitioner must be able to demonstrate that the procedures used have prevented the adventitious transfer of evidential material between two sources including themselves.

2. Security of all items must be assured by recording the names of all individuals having contact with them. This is usually achieved by signing an attached label. Leaving items unattended in the forensic science laboratory must also be avoided.

3. Careful permanent, contemporaneous records should be kept at each stage of the laboratory examination to avoid any possibility of confusion by assigning results to the wrong item.

4. All the procedures and methods used by the forensic scientist should be fully documented and any decisions justified. These are often referred to as Standard Operational Procedures (SOPs) and Standard Methods. Forensic science providers should normally have a comprehensive system detailing procedures to be followed and methods to be used. One of the important points here is to recognise that because it’s written down it does not need to be followed religiously if there’s a better way. One must always be aware of continual improvement and follow the SOP for improvements. However, the final source of assurance is the competence and integrity of individuals.

Over many years there has been an increasing call for third party accreditation of forensic science laboratories, in common with many other scientific laboratories and industrial organisations. In the USA this call has been met by the American Society of Crime Laboratory Directors through their Laboratory Accreditation Board. Under the auspices of this board the organisation, staffing and facilities of a laboratory are subjected to evaluation and on-site inspection before accreditation. A full re-inspection is carried out every 5 years. A good proportion of the many forensic science laboratories in the USA have been accredited by this process, and some in other parts of the world, especially Europe, Asia and Australia through alternative international accreditation bodies which may also have signed up to the ILAC (International Laboratory Accreditation Cooperation) Agreement.

Given the smaller number of laboratories in the UK it has proved more convenient to use a well-established system of accreditation applicable to all laboratories offering testing services to a client. The United Kingdom Accreditation Service (UKAS) is recognised by the government as the body for accrediting all types of laboratories and in this role UKAS established a number of standards, all of which have now been subsumed under the standards previously mentioned; ISO/IEC 17020 (Scene work) and ISO/IEC 17025 (Laboratory work and associated management) and ISO 9000. However, with a truly integrated investigative process it could be argued that one standard covering the whole process would be more appropriate. All of these processes are being internationalised through the ILAC organisation. Clearly, the wider recognition will be of great value to laboratories engaged in work supporting trade across international boundaries. However, given the increasingly international nature of crime, the concept of all forensic laboratories working to a common high standard has its attractions.

The accreditation process involves a series of steps. The applicant organisation, SME or sole trader submits documentation, including its quality manual, to UKAS who then assign a Technical Officer and a Lead Assessor to be responsible for advising whether the forensic provider should be accredited. This advice will be based on a pre-assessment visit for informal discussion and a broad review of the quality system followed by a formal inspection of the provider by an assessment team. At the end of the inspection the team will discuss any non-compliance found and agree the appropriate corrective action. If the assessment team is satisfied with the corrective actions, UKAS will review all the evidence and decide whether to accredit. Following accreditation, the provider will be subjected to regular surveillance and re-assessment visits to ensure that standards are being maintained.

Forensic scientists are required to tackle a wide variety of scientific analytical problems, many of which have no commercial analogue. This means that widely publicised and used methods such as those of the British Standards Institution may not be an option. As previously mentioned (Section 1.1), the call for forensic scientists to develop the necessary degree of objectivity in the method applied to a particular problem requires one to consider the definition of an objective method or test. A former Forensic Science Working Group that took part in formulating standards for forensic science spent much time in defining what was meant by an objective test. Their definition was that an objective test is one which, having been documented and validated, is under control so that it can be demonstrated that all appropriately trained staff will obtain the same results within defined limits.

Objective tests are controlled by:

1. Documentation of the test.

2. Validation of the test.

3. Training and authorisation of staff.

4. Maintenance of equipment.

and where appropriate by:

1. Calibration of equipment.

2. Use of appropriate reference materials.

3. Provision of guidance for interpretation.

4. Checking of results.

5. Testing staff proficiency and continual staff development.

6. Recording of equipment/test performance and measurement of uncertainty.

7. Consider latest innovations and technology for future applications.

For a sole trader, SME or large organisation to become accredited the individual forensic scientists performing any method need to be deemed competent and proficient. However, these two terms are closely related, much debated and often confused. In summary, competency refers to an individual’s continual ability to successfully carry out a ‘task’ to a particular standard. Proficiency relates to the high degree of skill and expertise to carry out a task. Both terms involve the application of knowledge and skill, with competency being the essential skills that are continually required for a certain task and proficiency implying the mastery of them. The aspect of personal accountability is further explored in Section 1.6.

The ultimate role of the forensic scientist is the presentation, either written as a witness statement or report, or verbal direct to the court as a professional or expert witness (skilled witness in Scotland). In fulfilling this role, the witness is completely and solely accountable for the work carried out, experimental results presented and for the facts or opinions expressed. If appearing as an expert witness then it is the court which decides if the witness is to be accepted as an expert and therefore permitted to express an opinion as opposed to the provision of fact. The expert witness is viewed by the court as rather special in that they are permitted to express an opinion. There has been much debate surrounding the role of the expert witness specifically from the law commission. Expert opinions must be justified to the court, often in the face of fierce cross-examination, and the witness cannot shelter behind the laboratory manual or base an opinion on a consensus or majority vote. This requires the witness to be a professional in the best sense of the word: that is, to have an initial developed competence which is continuously maintained and advanced (i.e. proficient) together with a powerful sense of balance, honesty and integrity. Clearly an employing organisation has a responsibility in this respect, but there may be additional assurance to the court through qualifications, experiences, expertise and memberships – such as professional body membership. The latter would seek to provide evidence of competence with a code of conduct and advice on professional behaviour. Given the nature of forensic science a range of appropriate professional bodies exist.

During the late 1990s the need for a ‘professional body’ was recognised and resulted in a register of competent forensic scientists being developed. This was held by the Council for the Registration of Forensic Practitioners (CRFP), an independent regulatory body to promote public confidence in forensic practice in the UK. Initially the introduction of the CRFP was viewed as a major step forward for the forensic science profession in the UK. However, the criteria used for registration were not necessarily ‘standards’ in the accepted meaning of the word and on 31 March 2009 the CRFP ceased operation, primarily due to lack of funding and unsuccessful attempts to become self-funded.

With the demise of the CRFP, the question was then raised about how to replace it. The FSR issued a consultative paper reviewing the options for the accreditation of forensic scientists. The outcome, although not necessarily covering all forensic scientists within the investigative process, was to have all forensic science laboratory functions accredited to an ISO standard. This would be carried out by UKAS, which would not only cover the practices and procedures but also look at a proportion of individuals’ cases, competency, proficiency and training records. However, there still remained a gap to be filled for the independent specialist expert not necessarily employed by a main forensic provider. A further consequence of the loss of the CRFP was the loss of the register. There are other registers held by various bodies, but the overall criteria to be accepted on the register varies and a national gap remains in this regard.

Another body that was involved with drawing up standards of competence (Table 1.3) for forensic scientists in the UK was SEMTA (Science, Engineering and Manufacturing Technologies, and formerly the Forensic Science Sector Committee of the Science, Technology and Mathematics Council) and Skills for Justice, two of the government Sector Skills Councils. Skills for Justice represents employers in the Justice sector including the Fire and Rescue sector. It was formed in 2004 and has the overarching mission to help organisations and individuals within these sectors to maintain a safe and just society. It does this through workforce skills and influencing policy at all levels to ensure it takes each sector’s workforce into account. To date, its greatest impact on the Justice and Fire and Rescue sectors could arguably be its review and 2007 updating of the National Occupational Standards (NOS) for forensic science, which had previously been owned by SEMTA. Skills for Justice in consultation with industry practitioners have reviewed and developed NOS in three areas—Crime Scene (evidence recovery from the crime, CSI, SOCOs, etc.), Forensic Identification (fingerprints, footwear, marks, DNA, etc.) and Forensic Laboratories (conducting forensic science laboratory investigations and analysis). The Fire and Rescue Service became a subscriber to Skills for Justice in 2009 and NOS are also available for this area. The NOS specify the standards of performance which practitioners are expected to achieve in their work and the knowledge and skills which they need to perform effectively, i.e. they describe competent performance in terms of the outcomes of an individual’s work. Skills for Justice remain the custodian of the NOS which are normally reviewed every three years or when the employer instigates a review.

As introduced earlier, it is important to have an overall QMS which can ensure practices and procedures. However, individual competency is integral to a successful profession and Table 1.4 shows how this can be implemented. Having described standards of competence it then becomes necessary to develop a strategy for assessing scientists against such standards and such assessment strategies are presently being developed.

To further support the continual development of individuals’ professional competence and to promote the development and dissemination of new scientific and investigative methods within the sector, a range of forensic science journals are published internationally. This includes Science & Justice, (formerly the Journal of the Forensic Science Society, 1960–1994) published by the CSFS. In a similar way to the University of Durham (in collaboration with the predecessor to the College of Policing), the CSFS once offered practitioners professional and postgraduate diplomas. The Society’s diplomas also offered a stepping-stone to a master’s degree with the option of an additional research project at either the University of Strathclyde or Staffordshire University. Although both the Durham and CSFS diplomas have now ceased, the CSFS introduced Certificates of Professional Competence (CPC) in a growing range of disciplines. Like the previous diplomas, there is a strong element of practical assessment, and the overall model includes the initial application, online questions in the applicant’s specialised area as well as questions on the legal framework within which they work. This is followed by a practical assessment based on the typical work carried out by the practitioner and a supporting statement or report. The CSFS gained its Royal Charter in 2013 enabling it to offer ‘Chartered’ status to its practitioners. The diversity of offerings provided by the CSFS further support the ISO standards in relation to individual competence and professional judgement.

Due to the breadth of disciplines that span forensic science activities, it is important to recognise that professional membership and educational accreditation are also sought from other professional bodies who are actively involved in developing and nationally implementing changes in quality standards, policy and nationally endorsed codes of practice within forensic science. Examples include the Royal Societies of Chemistry and Biology, Royal Anthropological Institute, Chartered Institute for Archaeologists, UK Association of Fire Investigators and the Institute of Fire Engineers. Another Society within the investigative process was The Fingerprint Society (FPS), founded in 1974 as a learned Society for fingerprint examiners. Its aim was to ‘advance the study and application of fingerprints and to facilitate the cooperation among persons interested in the field of personal identification’. Unfortunately, the Fingerprint Society proved unviable and merged with the CSFS in 2016.

A final area of interest and importance to forensic science practice over recent years has been that of cognitive bias. This is a situation when you are unaware that you are being influenced in making your decisions such that you may not make a personal, independent, honest decision. As way of example, consider the scenario where a stamped-in engine or chassis mark on a car or motor bike has been deliberately erased. The process to recover the number appears to be successful and some digits are being recovered by chemical treatment. During the quality assurance process you are asked check the digits and whether you can see the ‘8’? The very fact that the digit ‘8’ was mentioned means you are unduly influenced as it may also be a ‘3’ or a ‘5’ depending on the style of the numbers. In fact, it might not be a number at all and may be a letter. Being provided with some information this can be termed confirmation bias creating a cognitive influence and bias. The forensic scientist must be aware of such situations and ask the ‘checker’ the appropriate questions, and the ‘checker’ must also ensure they provide an independent review.

Other forms of bias include contextual bias, meaning that an individual has been influenced by others and therefore their decision may not be fully their own and they do not necessarily appreciate the impact of the other information. This has been investigated extensively by a range of authors across numerus forensic disciplines and can occur at many stages during an investigation. Hence, anyone involved must be fully aware of the impact and minimise bias whilst performing their duties. Some of the authors discuss issues of bias within their own particular discipline in this book. However, for a fuller understanding of this topic, readers are referred to other chapters in this book where the precautions and comments are relevant and transferable to many other forensic disciplines.

The discussion in this chapter has aimed to provide the reader with a background understanding of forensic science and the role of forensic scientists across the UK. It also covers how they achieve professional status and how the word ‘forensic’ implies working and interacting with the legal process. Working as a forensic scientist can be physically, emotionally and intellectually demanding, but also very satisfying and personally rewarding. The succeeding chapters will show why this is so.

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• Encyclopedia of Forensic Sciences, ed. M. M. Houck, Elsevier, Amsterdam, 3rd edn, 2022.

• G. S. Morrison, Advancing a paradigm shift in evaluation of forensic evidence: The rise of forensic data science, Forensic Sci. Int. Synergy, 2022, 5, 100270.

• C. Roux, R. Bucht, F. Crispino, P. De Forest, C. Lennard, P. Margot, M. D. Miranda, N. NicDaeid, O. Ribaux, A. Ross and S. Willis, The Sydney Declaration – revisiting the essence of forensic science through its fundamental principles, Forensic Sci Int., 2022, 332, 111182.

• Science and Technology Select Committee, Forensic science and the criminal justice system: a blueprint for change, Parliament, London, 2019, https://publications.parliament.uk/pa/ld201719/ldselect/ldsctech/333/33302.htm.