A diagnosis of the primary difference between<scp>EuroForMix</scp>and<scp>STRmix</scp>™
John Buckleton, Mateusz Susik, James M. Curran, Kevin Cheng, Duncan Taylor, Jo‐Anne Bright, Hannah Kelly, Richard Wivell
Abstract
Abstract There is interest in comparing the output, principally the likelihood ratio, from the two probabilistic genotyping software EuroForMix (EFM) and STRmix™. Many of these comparison studies are descriptive and make little or no effort to diagnose the cause of difference. There are fundamental differences between EFM and STRmix™ that are causative of the largest set of likelihood ratio differences. This set of differences is for false donors where there are many instances of LR s just above or below 1 for EFM that give much lower LR s in STRmix™. This is caused by the separate estimation of parameters such as allele height variance and mixture proportion using MLE under H p and H a for EFM. This can result in very different estimations of these parameters under H p and H a . It results in a departure from calibration for EFM in the region of LR s just above and below 1.