Rejecting defense claims that the trial court erred in admitting DNA evidence produced using STRmix™ -- sophisticated forensic software used to resolve mixed DNA profiles previously thought to be too complex to interpret – the Indiana Court of Appeals has affirmed the murder conviction of Keith B. Ivory, Jr. (Ivory v. State of Indiana, Court of Appeals Case No. 18A-CR-2575)
Ivory was convicted in the St. Joseph Superior Court of killing Bethel Smallwood, whom he believed was at least partially responsible for the death of his sister in 2013. STRmix™ testing of a t-shirt and handgun linked to the murder revealed a strong likelihood that the t-shirt and a moderate likelihood that the handgun contained DNA contributed by Ivory.
The Court of Appeals disagreed with the defense’s contention that STRmix™ is relatively new, and its results were of low statistical value which would confuse the jury. In affirming the lower court decision, the Court noted, “The age of a DNA analytical procedure is not, itself, a reason to exclude evidence … [Moreover] there is ample evidence to support a conclusion that the probative value of DNA evidence outweighed any confusion or undue prejudice.”
Since its introduction in 2012, STRmix™ has been used to interpret DNA evidence in more than 120,000 cases around the world. It has also been used successfully in numerous U.S. court cases, including 28 successful admissibility hearings.
STRmix™ is currently being used by forensic labs at 55 U.S. agencies – including the FBI and the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) – and is in various stages of installation, validation, and training in more than 60 other U.S. organizations.
According to John Buckleton, DSc, FRSNZ, one of the developers of STRmix™, forensic labs have turned to STRmix™ “because it greatly improves the usability of DNA to produce evidence in a wide range of criminal cases.” He 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 proving to be highly effective in delivering a significantly higher rate of interpretable results in sexual assault cases.
A new 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.