STRmix™ – sophisticated forensic software for resolving mixed DNA profiles previously thought to be too complex to interpret – has now been used in over 120,000 cases worldwide since 2012, according to a new survey.
The survey, conducted by New Zealand’s Institute of Environmental Science and Research (ESR), indicates that over 3,600 of the cases have been presented in court. In addition, STRmix™ evidence was presented in over 40 successful admissibility hearings.
The survey also shows that slightly more than half of the cases using STRmix™ (nearly 53%) were reported in North America. Of the remaining cases, nearly 90% occurred in Australia and New Zealand.
“That caseload distribution makes perfect sense, given those countries where STRmix™ is predominantly used,” says Jo-Anne Bright, PhD, Senior Science Leader at the New Zealand Institute of Environmental Science and Research (ESR), and one of the developers of STRmix™.
According to Dr. Bright, 46 agencies in the U.S. now use STRmix™, including the FBI, ATF, numerous state agencies, and even private companies such as Bode Cellmark Forensics. STRmix™ is also being used in all nine state and territory labs in Australia and New Zealand, as well as 12 forensic labs in England, Scotland, Ireland, Finland, Dubai, Denmark, and Canada.
John Buckleton, DSc, FRSNZ, Forensic Scientist at ESR, and one of the developers of STRmix™, attributes the widespread use of STRmix™ to the way in which “it has improved the usability of DNA. As a result, a growing number of forensic labs around the world are turning to STRmix™ to produce usable DNA evidence in a wide range of criminal cases.”
Dr. Buckleton notes that agencies using STRmix™ are reporting an increase of interpretable DNA in gun cases from about 40% to more than 70%. STRmix™ is also delivering a significantly higher rate of interpretable results in sexual assault cases, producing a strong return on investment while enabling staff to clear Sexual Assault Kit backlogs.
Looking to the future, the survey shows that over half of responding forensic labs would be interested in using STRmix™ in the cloud to interpret higher order mixtures for casework.
STRmix™ is expected to introduce a new version of its software later this year. It recently launched DBLR™, an application for rapidly calculating likelihood ratios, which are used to assess the strength of DNA evidence and how likely it is that DNA found at a crime scene belongs to specific individuals. Used in conjunction with STRmix™, DBLR™ can calculate millions of likelihood ratios in seconds.