WASHINGTON (PRWEB) February 22, 2018
STRmix™ – the sophisticated forensic software used to resolve mixed DNA profiles previously thought to be too complex to interpret – has been used to charge suspects in two separate murder cases in Florida.
In the first case, police used STRmix™ to decipher DNA mixtures found on a firearm, clothing, and other items found in a car stolen from the Jupiter, FL home at which the February 2017 shootings took place. This allowed investigators to arrest and charge Marcus Steward with the murders of Sean Henry, Brandi El-Salhy, and Kelli Doherty. Another individual, Christopher Vasata, previously had been arrested in the case.
Use of STRmix™ in a second case enabled the Sarasota County (FL) Sheriff’s Office to charge Delmer Smith with murder and sexual battery in the April 2009 death of Georgann Lee Smith. STRmix™ was used by DNA Labs International to interpret multiple profiles of DNA extracted from the victim’s clothes, and ultimately identify Delmer Smith’s DNA.
Smith is currently housed at Florida State Prison in Raiford after being sentenced to life in prison for armed home invasion and armed kidnapping in one Sarasota case, and sentenced to death for the first-degree murder of Kathleen Briles in a Manatee case. He now will be transported back to Sarasota County to face charges in the Georgann Lee Smith case.
The two Florida murder cases are among the most recent in the U.S. to successfully use STRmix™. In December, evidence produced by STRmix™ was used to convict a Brooklyn, NY man of murder for slashing the throat of his estranged wife. In that case, STRmix™ was able to isolate the defendant’s DNA in several pieces of evidence presented during the trial.
Thirty U.S. forensic labs now routinely use STRmix™ in resolving DNA profiles. These include everything from federal agencies such as the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) and the FBI to state and local agencies, including the Michigan State Police, Texas Department of Public Safety, and the California Department of Justice.
STRmix™, which recently celebrated its fifth anniversary of use in live casework, is also in various stages of installation, validation, and training in 56 other U.S. labs.
“In five short years, STRmix™ has moved from being an experimental technology to the broadly accepted norm in cases in which a sophisticated forensic software is required to resolve mixed DNA profiles,” says John Buckleton DSc, FRSNZ, Forensic Scientist at the New Zealand Institute of Environmental Science and Research (ESR). Buckleton developed STRmix™ in collaboration with ESR’s Jo-Anne Bright and Duncan Taylor from Forensic Science South Australia (FSSA).
ESR launched an upgraded version of STRmix™ in mid-2017. STRmix™ v2.5 contains a number of new features designed to improve functionality, speed, memory, and ease of use, including: multi-kit functionality, enabling interpretation of DNA profiles from different test kits; a likelihood ratio (LR) batcher tool, allowing users to calculate multiple LRs from multiple reference inputs to a previously run deconvolution; and a combined DNA Index System (CODIS) report.