Chapter 9: Trace and Contact Evidence Check Access

Trace evidence refers to minute samples of material other than those which are biological in nature. A wide range of trace materials are encountered in casework at forensic laboratories. These range from those which are examined routinely and subject to standard operating procedures, including glass, paint and fibres, through to those which are rarely encountered, examples being glue, pen ink, and glitter. The examination of these rarely encountered trace materials will rely on the skill and experience of the forensic scientist as well as the various techniques of examination available to them. This chapter describes the assessment, laboratory examination and interpretation of trace evidence cases in general terms as well as the various techniques of analysis available at the laboratory. The chapter will then move on to consider each of the trace evidence types routinely encountered at the laboratory in greater depth, specifically glass, paint, fibres, condom lubricants and noxious chemicals, including case studies. The chapter will conclude with a look at examples of cases involving rarely encountered trace evidence types including how these cases were tackled and interpreted by the forensic scientist.