The North Carolina State Crime Laboratory has begun using STRmix™ v2.7, sophisticated forensic software used to resolve mixed DNA profiles previously thought to be too complex to interpret.
Introduced in late 2019, STRmix™ v2.7 builds on previous versions of STRmix™, while adding several key new features including a variable number of contributors (varNOC) for multi-kits and the ability to compare two or more DNA mixtures to find a common contributor. The new features were added in response to improvements recommended by forensic labs to better address on-the-job needs they regularly encounter.
The North Carolina State Crime Laboratory becomes the 57th forensic lab in the U.S. now using STRmix™ to interpret DNA profiles in criminal investigations. 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, local, and private forensic laboratories.
With a full-service laboratory in Raleigh, a Western Regional Crime Lab in Edneyville, and a Triad Regional Crime Lab in Greensboro, the North Carolina State Crime Laboratory examines evidence related to criminal investigations free of charge for any North Carolina public law enforcement agency, including local, state, federal, military, and railroad police organizations.
The laboratory also provides consultation on the value, use, collection, and preservation of evidence; expert testimony in court proceedings; and assistance in collecting evidence and processing crime scenes.
Since its introduction eight years ago, STRmix™ has been used to interpret DNA evidence in more than 160,000 cases worldwide. It has also been used successfully in numerous U.S. court cases, including at least 37 successful admissibility hearings.
“Demand for STRmix™ is high due to its success in producing usable, interpretable, and admissible DNA results in a wide range of criminal cases,” says John Buckleton DSc, FRSNZ, Forensic Scientist at the New Zealand Institute of Environmental Science and Research (ESR) and one of the developers of STRmix™.
Currently in various stages of installation, validation, and training in more than 60 other U.S. organizations, STRmix™ has also proved to be effective in helping to solve cold cases in which evidence originally was dismissed as inconclusive.
The team that created STRmix™ recently launched two other products. DBLR™, an application used with STRmix™, allows users to undertake superfast database searches, visualize the value of their DNA mixture evidence, and carry out mixture to mixture matches. FaSTR™ DNA, meanwhile, is expert forensic software that rapidly analyzes DNA profiles and assigns a Number of Contributors (NoC) estimate.
Designed by scientists for scientists, FaSTR™ DNA combines an intuitive, user-friendly graphical interface with easily understandable and laboratory-customizable rules to expedite the analysis of raw data generated by genetic analyzers and standard profiling kits. FaSTR™ DNA also implements the use of artificial neural networks for peak classification independent of and in parallel to the forensic analyst.
Alongside STRmix™, FaSTR™ DNA and DBLR™ complete the full workflow from analysis to interpretation and database matching.