Statistical analyses to support forensic interpretation for a new ten-locus STR profiling system

A new ten-locus STR (short tandem repeat) profiling system was recently int roduced into casework by the Forensic Science Service (FSS) and statistical analyses are described here based on data collected using this new system for the three major racial groups of the UK: Caucasian, Afro-Caribbean and Asian (of Indo-Pakistani descent). Allele distributions are compared and th e FSS position with regard to routine significance testing of DNA frequency databases is discussed. An investigation of match probability calculations is carried out and the consequent analyses are shown to provide support fo r proposed changes in how the FSS reports DNA results when very small match probabilities are involved.