Validation of a frequency database for four STR loci for use in casework in the Strathclyde Police Forensic Science Laboratory

Data for four STR loci have been collected from 400 samples taken from complainers and suspects encountered in casework at the Strathclyde Police Forensic Science Laboratory (SPFSL). This paper describes statistical testing which demonstrates that its use will provide operationally robust procedures. Comparisons made with data collected from other British samples confirmed no practical differences between the different frequency distributions. This work provides further confirmation of the reliability of the so-called ‘product rule’ in estimating the frequency of multilocus genotypes in British forensic casework.