The Contra Costa County, CA Office of the Sheriff and New York’s Suffolk County Crime Laboratory are the latest U.S. organizations to announce they will use STRmix™ to interpret DNA profiles in criminal investigations.


STRmix™, which was developed in New Zealand and Australia, is sophisticated forensic software that can be used to resolve mixed DNA profiles previously thought to be too complex to interpret.


The addition of the two new organizations brings the total number of forensic labs using STRmix™ nationally to 55. That list includes federal agencies such as the FBI and the Federal Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF), as well as numerous state and local organizations throughout the country. In addition, STRmix™ is currently in various stages of installation, validation, and training in more than 60 other U.S. organizations.


The Suffolk County Crime Laboratory provides a wide variety of forensic services to the Suffolk County District Attorney’s Office, the Suffolk County Police Department and all other Police Departments within the county, the New York State Police Department, and the United States Attorney’s Office.  Services are also provided to the County Attorney’s Office in civil matters. 


The Contra Costa County Office of the Sheriff is the largest law enforcement agency in Contra Costa, with over 1,100 sworn and professional employees dedicated to providing the highest level of law enforcement and customer services. The Office of the Sheriff offers a full range of services to more than 1,000,000 residents in the 715-square-mile county.


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 35 successful admissibility hearings.


“Forensic labs using STRmix™ are experiencing a marked increase of usable, interpretable, and admissible DNA results in a wide range of criminal cases, including evidence from guns, other touch evidence, and sexual assault evidence,” explains John Buckleton DSc, FRSNZ, Forensic Scientist at the New Zealand Institute of Environmental Science and Research (ESR) and one of the developers of STRmix™.


Buckleton notes that STRmix™ has proved to be particularly 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.

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