PLACERVILLE (CBS13) — Although DNA evidence has been used countless times before to locate a cold case murder suspect, Ricky Davis’ El Dorado Hills murder case became the second time in history someone incarcerated was exonerated due to genealogy DNA.
Davis, 54, walked out of prison an exonerated man on Thursday after being wrongly convicted in 2005 of killing his roommate Jane Hylton in 1985.
Investigators said Thursday they could not have exonerated Davis in this way even two years ago. That is how fast genealogy DNA crime-fighting has advanced in recent years. But the DNA exonerations are certainly not new.
The Innocence Project — a non-profit committed to exonerated wrongly incarcerated individuals through the use of DNA testing — says at least 367 people have been exonerated thanks to DNA evidence. Serving an average of 14 years each, 21 of those 367 people were on death row.
But this is the only the second time genealogy DNA was used to exonerate an innocent man, by leading to the prosecution of a different suspect.
In this case, they took a DNA sample from a bite mark on the victim’s nightgown and used the same genealogy techniques as in the Golden State Killer case.
First, investigators uploaded the DNA sample to a public ancestry site, then built a family tree based on unique genetic makers, before narrowing the relatives down to someone with motive or means.
So far, there have been at least 60 cold case arrests based on genealogy DNA. But the El Dorado County District Attorney says this is only the second time that an arrest led to the exoneration of someone else who’d been falsely convicted in the country. The other was the Angie Dodge case in Idaho.