The addition of crime labs in Wisconsin and Louisiana brings to 53 the number of forensic laboratories in the United States now using STRmix to resolve DNA profiles in criminal investigations.
Developed in New Zealand and Australia, STRmix is sophisticated forensic software that can be used to resolve mixed DNA profiles previously thought to be too complex to interpret.
The newest U.S. labs using STRmix are the Jefferson County (Louisiana) Sheriff’s Office Regional DNA Laboratory, which includes a traditional crime lab, a photo lab, and a DNA lab, and the Wisconsin State Crime Laboratories, part of the recently reorganized Wisconsin Department of Justice Division of Forensic Sciences.
The Wisconsin lab provides crime scene response, toxicology, drug identification, DNA analysis, firearms and tool marks analysis, fingerprint and footwear analysis, ten print comparison, photo work, and forensic imaging.
These labs join a national list of forensic labs using STRmix that now includes the FBI and the Federal Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). In addition, STRmix is currently in various stages of installation, validation, and training in more than 60 other U.S. organizations.
Since its introduction in 2012, STRmix has been used to interpret DNA evidence in more than 120,000 cases worldwide. It has also been used successfully in numerous U.S. court cases, including 28 successful admissibility hearings.
John Buckleton DSc, FRSNZ, Forensic Scientist at the New Zealand Institute of Environmental Science and Research (ESR) and one of the developers of STRmix, attributes the increased use of STRmix to “its success in producing usable, admissible DNA evidence in a wide range of criminal cases.”
According to Buckleton, forensic labs using STRmix are experiencing a marked increase of interpretable DNA results from guns, other touch evidence, and sexual assault evidence. The software is also proving to be effective in helping to solve cold cases in which evidence originally dismissed as inconclusive has been reprocessed, as well as in supporting exonerations of wrongly convicted individuals through reexamination of inconclusive results in post-conviction cases.
The latest version of STRmix, STRmix v2.7, was introduced in late 2019. STRmix v2.7 includes several new features in response to improvements recommended by forensic labs to better address the on-the-job needs they regularly encounter.
DBLR, an application used with STRmix, was also introduced last year. DBLR allows users to undertake superfast database searches, visualize the value of their DNA mixture evidence, and carry out mixture to mixture matches.