A new version of STRmix is now available following nearly a year of extensive development and testing.
STRmix Version 2.8 features a top-down approach that allows users to set the number of major contributors to a mixed DNA profile in which there is interest, and then obtain a likelihood ratio (LR) only for those contributors. This approach will enable users to tackle more complex profiles faster.
"The top-down approach incorporated into STRmix v2.8 is in direct response to recommendations made by forensic labs to better address the on-the-job needs they regularly encounter," says John Buckleton, FRSNZ, Forensic Scientist at the New Zealand Institute of Environmental Science and Research (ESR) and one of the developers of STRmix. "Ultimately, this allows high through-put screening of the profile to provide investigative intelligence regarding the major contributors in complex mixtures."
The new version of STRmix also contains improved modelling and memory usage features.
STRmix Version 2.8 comes nearly a year to the day after the introduction of Version 2.7. Building on previous versions of the software, STRmix v2.7 featured the addition of a variable number of contributors (varNOC) for multi-kits and the ability to compare two or more DNA mixtures to find a common contributor.
Since its introduction in 2012, STRmix has proven to be highly effective in producing usable, interpretable, and admissible DNA results in a wide range of criminal cases, including violent crime and sexual assault cases. It has also been instrumental in helping to solve cold cases in which evidence originally was dismissed as inconclusive.
"Demand for STRmix has been extremely high due to the critical role it plays in helping to solve crimes and excluding individuals who have been wrongly associated as the source of crime scene evidence," explains Buckleton.
To date, STRmix has been used to interpret DNA evidence in more than 160,000 cases worldwide. That number includes numerous U.S. court cases, including at least 37 successful admissibility hearings.
In addition to the U.S. agencies currently employing STRmix in criminal investigations, the software is now in various stages of installation, validation, and training in more than 60 other organizations.