The importance of forensic statistics

Forensic statistics is the application of statistics to forensic science and the law.

Broadly speaking, forensic science is the analysis of traces of evidence (such as body fluids, glass fragments, footprints and drugs) left at the scene of a crime by the criminal, victim or others. This evidence may be used subsequently to either implicate or exonerate a person suspected of committing that crime, or just to gain further insight into the incident. Over the years, with increasing technological advancement, forensic science has become a key part of criminal investigations worldwide.

But forensic science doesn't just involve identifying traces of evidence - sometimes it isn't obvious just what a piece of evidence really is. Other important questions that need to be answered are just how the evidence came to be at the crime scene, where did it originally come from, and who left it there. This suggests a natural role for statistics, as these questions can typically only be answered in terms of probabilities. So it is not surprising that the primary task of forensic statisticians is to evaluate any evidence found at a crime scene, so that this evidence can be appropriately presented to a jury in court. This task obviously carries great responsibility.

The advent of DNA profiling in the 1980s brought a big change in the way the legal system viewed quantitative data. Now a quantitative approach is being requested in many areas, far removed from the original area of DNA profiling. The earlier research and development work is being applied and further work is being done to tackle the increasingly more complex cases which arise in bringing a sound statistical approach to the assessment of evidence.