Statistics & the Art of Forensic Science

Alan J. Izenman, Department of Statistics, Temple University, Philadelphia, USA

Statistical thinking and practice can make a substantial contribution to the manner in which forensic science is handled in the laboratory and the courtroom.  In this talk, I discuss how statistical methods can be used to  compare forensic measurements obtained from DNA profiling from different sources, such as evidence left at a crime scene and whatever information can be retrieved from a database.  I discuss two important issues.  First, I examine the assumption of independence of alleles in calculating probabilities of a match in DNA profiling, and then I discuss how the calculation of match probabilities obtained from a database search, as are used in DNA profiling and fingerprint identification, can be improved by taking the nature of the search process into account. The application of sophisticated statistical techniques to forensic science is still very much in its infancy and it is hoped that more can be done to encourage a greater level of cooperation between forensic scientists and statisticians.