ABSTRACT
The purpose of examining forensic evidence is to support the investigation of crime by identifying or eliminating individuals, testing investigative hypotheses and reconstructing events of investigative or legal significance. During the past 25 years forensic science has moved from being an investigative option to a core aspect of criminal investigation, from being corroborative evidence to an inceptive tool. This shift is a consequence of the significant benefits to police investigations and criminal justice more generally deriving from the development and global expansion in the use of forensic science. This expansion cannot be wholly explained or understood with reference to science or technology alone, but must be considered in light of a complex web of social, political, legal, economic and professional factors.2 While it is true to say that many of these developments can be traced to the discovery of DNA profiling by Sir Alec Jeffreys in 1986, which acted as a catalyst, the impact of this discovery and the trajectory of developments varied in different jurisdictions. In England and Wales, as a consequence of political imperatives, legislation and funding followed these technological developments, leading to the implementation of what was the first, and is now the largest, DNA database in the world. The trajectory of development in Scotland and most other countries was less dramatic in that legislation was slower to arrive and limited funds were set aside for the use of DNA. All of these developments must be seen against a background of broader societal factors which include a gradual loss of trust in the police and other professions, increased requirements for transparency and increased litigiousness, which have resulted in the need and expectation of more reliable and objective evidence in criminal investigations.
