TrueAllele solves uninterpretable DNA in mother and daughter double homicide

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When DNA is not enough – exoneration through science

G. Hampikian, M.W. Perlin, and F.L. Watson, "When DNA is not enough – exoneration through science", Promega's Twenty Seventh International Symposium on Human Identification, Minneapolis, MN, 27-Sep-2016.


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In 1989, five men gang-raped a motorist after bumping her car. Darryl Pinkins and two other innocent men were misidentified as her attackers through stolen clothing. Pinkins was convicted of rape in 1991, and sentenced to 65 years in prison.

In 1995, Pinkins contacted the Innocence Project. In 1999, they in turn contacted Fran Watson, clinical professor at the Indiana University Wrongful Conviction Clinic. Watson and her students represented Pinkins, and codefendant Roosevelt Glenn, through decades of unsuccessful state post-conviction and federal habeas corpus proceedings.

In these proceedings it was shown that the state used false science to convict the men. There was faulty hair comparison testimony, and irrelevant blood typing inclusion evidence. Yet the courts labeled this flawed evidence harmless.

A 2001 DNA analysis of semen on the victim’s jacket and sweater showed mixtures of two or more people. Each mixture had a clear 80%–90% major contributor that did not match the accused. But this limited DNA analysis was not enough to exonerate.

In 2007, Greg Hampikian of the Idaho Innocence Project began working with Watson. They showed that the blood typing evidence was incorrectly presented during trial and was irrelevant in light of DNA exclusions, including new post-conviction DNA evidence. But the court ruled that the 2 unidentified major DNA genotypes in the semen, plus the 3 accused, equaled the 5 perpetrators – so post-conviction relief was denied.

In 2014, Dr. Hampikian recruited Mark Perlin of Cybergenetics for pro bono assistance. The TrueAllele® system provided the science needed to establish innocence beyond doubt. More complete analysis of existing DNA data revealed the genotypes of all five perpetrators. This convinced the state that the wrong man had been convicted.

TrueAllele compared evidence with evidence to calculate exclusionary match statistics. It discovered new genotypes from 5%–10% minor contributors by jointly analyzing DNA mixture data. Kinship analysis showed that three of the perpetrators were brothers. These computer capabilities found the victim and 5 unidentified genotypes in the semen and hair evidence. The defendants were not linked to the crime.

Acceding to exculpatory DNA evidence found by science, Lake County Prosecutor Bernard Carter vacated Pinkins’ conviction. Instead of hearing newly analyzed DNA evidence, that morning the court released him from prison. Pinkins had spent 24 years in an Indiana prison for a crime he did not commit. Computer reanalysis of old DNA data proved that Pinkins and Glenn were innocent.