California authorities are combing through DNA left behind by dead killers, rapists and other criminals in an effort to solve cases that went cold years ago.
So far, the effort has linked a serial killer who died in prison in 1999 to an unsolved murder in Los Angeles County in 1990, the Los Angeles Times reported Saturday.
The program is not likely to result in additional convictions because the perpetrators are already dead. However, it can allow investigators to close some cases and turn their attention to others. It can also help bring closure to the families of victims.
"We owe it to these families whether the person is dead or not to provide the answers that they're entitled to. That's the primary goal,'' said Anne Marie Schubert, a supervising deputy district attorney in Sacramento who is leading the effort.
The case that was cracked involved serial killer Juan Chavez, who pleaded guilty to robbing and strangling five men in Los Angeles County in the mid- to late 1980s.
He committed suicide in Folsom Prison in 1999. Last year, investigators discovered coroner's officials in Sacramento still had blood collected during Chavez's autopsy.
They used it to compare his DNA with that found on a cigarette butt taken from the apartment of a man who had been strangled in 1990.
To find such evidence, prosecutors in Sacramento, Los Angeles and Orange counties have been searching through old crime-scene files, courtroom exhibits and other sources for DNA markers found in things like blood or saliva that was left behind.
They have even looked for envelopes inmates licked before mailing letters from prison to court officials. Authorities believe the effort is the first of its kind in the nation. During their searches, prosecutors have sometimes run into dead ends, particularly in decades-old cases where the evidence has long since been discarded and in cases where no autopsy was performed after a prison inmate died.
In Los Angeles County, Carol Burke, who heads the sex-crimes section of the District Attorney's Office, said she has collected genetic markers from five death row inmates after they died in prison.
So far none of them have led authorities to unsolved crimes, but Burke says that doesn't mean the effort wasn't worthwhile. "We solved one case, so to me that's rewarding and worth my time,'' she said.