According to a search performed in the Web of Science database using the keyword “forensic methods”, the number of analytical forensic methods has increased from one method, first reported by Marsh in 1836, to 18379 methods published in 2019. The results of this online search demonstrate that the number of analytical forensic methods for crime scene investigations has been increasing. While forensics is the current hot topic in Analytical Chemistry, with the expansion of forensic analysis literature, forensic science books still tend to be organized in distinct areas: drugs and poisons, forensic DNA analysis, and trace evidence. Because these are not very common undergraduate or graduate topics for chemistry courses, our aim was not to cover these distinct areas but rather to concentrate on the analytical chemistry instrumental techniques used for crime scene investigations. We have attempted to show that the specific technique used is vital to understanding or explaining the evidence in court.
The first chapter explains how chemical sensing using analytical techniques and methods was initially applied in forensic detection. This chapter also describes some criteria to be used in courtrooms as well as how various nonstandard forensic techniques could be helpful in crime scene investigations. Chapter 2 stresses the importance of sampling and sample preparation in providing accurate evaluation of crime scene evidence.
The fundamentals of the standard and non-forensic standard techniques are described in Chapters 3 through 9. In these chapters, the practical applications of the following techniques in forensic chemical sensing are discussed: atomic adsorption spectrometry, laser-induced breakdown spectroscopy, nuclear magnetic resonance spectroscopy, electrochemistry, scanning electron microscopy, Fourier-transform infrared spectroscopy, near infrared spectroscopy, and paper spray ionization mass spectrometry. Chapter 10 describes current practice in the field, highlighting the development of portable detectors that are needed for forensic science analysis on site. Chapter 11 discusses the use of epigenetic techniques to detect human cells left behind by suspects at crime scenes. These specific and sensitive techniques can identify a suspect’s age, lifestyle, and diet. This chapter also describes new tools available for crime scene investigations. Finally, Chapter 12 examines some of the challenges as well as the future of forensic analytical methods.
We would like to thank all the contributing authors for their enthusiasm and participation in the preparation of this book. We also would like to express our gratitude to the staff of the Royal Society of Chemistry, in particular Katie Morrey and Janet Freshwater, for their assistance in bringing this book to print and publication.