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TrueAllele® validated for complex DNA mixtures containing ten contributors
The Journal of Forensic Sciences (JFS) published an open-access preprint of a peer-reviewed study "Validating TrueAllele® Interpretation of DNA Mixtures Containing up to Ten Unknown Contributors" by David Bauer, Nasir Butt, Jennifer Hornyak, and Mark Perlin. The study found that "TrueAllele is a reliable method for analyzing DNA mixtures containing up to ten unknown contributors."
Most DNA evidence is a mixture of two or more people. But much of this evidence goes unreported, lost to criminal justice. When unable to fully interpret DNA data from mixtures of more than several people, artificial limits give "inconclusive" results. The result is injustice – criminals go free, while innocents are imprisoned.
This new study shows that human limits preventing DNA evidence interpretation are unnecessary. TrueAllele computer interpretation of crime laboratory data can draw reliable conclusions from previously "inconclusive" DNA evidence. Better science delivers better justice – criminals are convicted, and innocents go free.
Pittsburgh-based innovator Cybergenetics develops TrueAllele forensic technology. Cleveland-based Cuyahoga County Regional Forensic Science Laboratory uses TrueAllele software in its criminal casework. The two groups collaborated on the study, and jointly presented their results at the 70th Annual Scientific Meeting of the American Academy of Forensic Sciences.
"Mixtures combine the DNA of different people into one biological sample," wrote the authors; "the interpretation task is to un-mix the biological data." While "recovering input genotypes from output data is difficult for human analysts," the study shows it "can be accomplished using modern statistical computing."
In 2016, the President’s Council of Advisors on Science and Technology (PCAST) policy report "suggested limiting DNA mixture usage based on contributor number and mixture weight." However, the new TrueAllele study’s validation results show why "this forensic policy proposal is scientifically unfounded."
The validation paper urges respect for scientific data. "The study supports interpreting evidence based on data observation, not unknowable facts," wrote the authors. DNA data should be fully interpreted, not discarded by crime laboratories.
Criminal justice stakeholders – prosecutors and police, defenders and innocence groups, crime laboratories and criminal courts – rely on TrueAllele results for better justice through science®. The new JFS study extends previous testing, "establishing TrueAllele reliability on mixtures containing up to ten unknown contributors."
- Validating TrueAllele® interpretation of DNA mixtures containing up to ten unknown contributors – Validation Study