DNA Tests Requested by Death Row Inmate Tie Him to 4 Murders


DNA tests requested by a death row inmate provide strong evidence of his guilt in the 1983 murders of a Chino Hills couple, their 10-year-old daughter and an 11-year-old house guest, state Atty. Gen. Bill Lockyer said Tuesday.

Kevin Cooper, 44, was convicted in 1985 and sentenced to death for the murders of Douglas and Perry Ryen, their daughter Jessica and her friend, Christopher Hughes. The victims were stabbed and hacked repeatedly with a knife, ax and ice pick.

The killings occurred shortly after Cooper escaped from the nearby California Institution for Men at Chino, where he had been serving a burglary sentence.


Cooper contended from the outset that although he stayed in a vacant house near the Ryen home for two days after his escape, he had nothing to do with the murders. He said he had never been inside the sprawling hilltop ranch house in which the slayings occurred. The evidence against Cooper was circumstantial, and the lone survivor of the attack, an 8-year-old boy, gave conflicting testimony about the killer’s identity.

Cooper’s lawyers tried for years to get the state to perform DNA analyses that were not available when he was sentenced, but the state Supreme Court rejected the attorneys’ requests for the tests. Then, last year, acting under a recently enacted evidentiary law, the attorney general’s office agreed to order the tests.

Lockyer said the state Department of Justice laboratory tested several pieces of crime scene evidence, including a drop of blood found outside the bedroom where Doug and Peggy Ryen died, two cigarette butts found in the Ryens’ station wagon, which was believed to have been the killer’s getaway vehicle, and a bloodstained T-shirt found outside a bar.

“The results of this testing established a match between Kevin Cooper’s DNA and that found on the evidence from the murder scene,” Lockyer said.

The attorney general’s office said that although all the samples matched to a great degree, some matched more than others. Officials said that matching DNA samples is much like matching fingerprints: the more corresponding points of comparison, the more certainty that the samples came from the same source.

Nathan Barankin, a spokesman for Lockyer, said the maximum match was found between a sample of blood provided by Cooper and a sample from the drop of blood found outside the bedroom. In that case, Barankin said, the matching DNA codes are estimated to occur in about 1 in 310 billion African Americans.