STRmix Plays Key Role in Chicago Murder Trial

Share Article

Prosecution details how probabilistic genotyping using STRmix linked defendant to DNA evidence.

STRmix™ – sophisticated forensic software used to resolve mixed DNA profiles previously thought to be too complex to interpret – recently played a key role in the trial of a Chicago gang member accused of murdering nine-year-old Tyshawn Lee.

Jurors found Dwright Boone-Doty guilty of murder in the first degree for shooting Lee (Illinois v. Dwright Doty, 16CR 08715-02). He faces up to life in prison at sentencing.

The prosecution in the case detailed how probabilistic genotyping using STRmix™ had linked Boone-Doty to DNA evidence found on Tyshawn’s basketball.

Testifying in the case, STRmix™ co-developer John Buckleton, DSc, FRSNZ, noted that forensic analysis by the Illinois State Police found “very strong support” that Boone-Doty’s DNA contributed to the mix found on three out of four samples from the basketball and “strong support” for the fourth sample.

Buckleton testified that the analysis also found statistical support for Boone-Doty’s profile being included in the DNA mixture on several swabs taken from the alleged getaway car.

An accomplice of Boone-Doty, Corey Morgan, was also found guilty of the boy’s murder in a separate trial. A third man, Kevin Edwards, pleaded guilty to first-degree murder in exchange for a 25-year prison sentence.

The Cook County case marked the first time evidence produced by probabilistic genotyping had been used in a state court in Illinois.

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 47 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 another 60 U.S. labs. Internationally, it is being used by nearly two dozen forensic labs in Australia, New Zealand, England, Scotland, Ireland, Finland, Dubai, Denmark, and Canada.

According to Buckleton, 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 September. STRmix™ v2.7 includes several new features in direct response to recommendations for improvements made by forensic labs to better address the on-the-job needs they regularly encounter.

In addition, an updated STRmix™ Defense Access Policy gives defense legal teams even easier access to STRmix™ software. The updated Access Policy includes definitions of the extended items that can be provided under the policy, updated non-disclosure agreements (NDAs), and an abbreviated NDA for use in some specific circumstances.

For more information about STRmix™ visit

Share article on social media or email:

View article via:

Pdf Print

Contact Author

Ray Weiss
Weiss PR, Inc.
+1 (410) 303-5019
Email >