Kevin Cooper was convicted in 1985 of the gruesome murders of four people - including two children - in a Chino Hills home two years prior. A fifth victim's throat was slashed, but he survived. Cooper is facing the death penalty, but has maintained his innocence throughout the years.
So far, every appeal he's made has been denied.
"As you know I have very strong opinions about death, and the death penalty," Newsom said during a recent news conference. "I want to make sure it's done fairly and judiciously without any determination of bias."
The bodies of the murder victims were discovered on June 5, 1983 by a neighbor. Bill Hughes arrived at the home in Chino Hills where his 11-year-old son Chris had spent the night. In addition to finding his son dead, he found the bodies of Doug and Peggy Ryen, and their 10-year-old daughter Jessica. The Ryens' 8-year-old son Josh survived the attack.
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Kevin Cooper was considered a suspect early in the case. He had recently escaped from the California Institute for Men in Chino, and was staying in the vacant house next door to the Ryens' home. Authorities later collected evidence that included a green button with blood on it, a blood-stained rope in the closet, and a bloody T-shirt found alongside the road not far from the murder scene.
Although DNA testing wasn't available at the time of the trial, when tested nearly 20 years later, DNA evidence indicated a match to Kevin Cooper.
"You have a blood drop that was found in the hallway where the victims were murdered; that's Kevin Cooper's blood," said San Bernardino County District Attorney Jason Anderson, who said he's spent considerable time reviewing trial documents.
"You have a T-shirt that was introduced by the defense at trial, that was... tested in the 2000s. That turned out to be Kevin Cooper's blood and Doug Ryen's blood."
But Cooper's advocates have said abnormalities with the results indicate evidence may have been planted. U.S. District Court Judge William Fletcher, who dissented in the 9th Circuit Court of Appeals decision to deny Cooper's appeal in 2009, said he believed Cooper was framed.
Newsom said recent DNA results were also inconclusive in his eyes, which is why he's ordered an independent investigation.
"(Regarding) prosecutorial misconduct, I'm not suggesting any of that is at play," said Newsom. "I am suggesting that based upon the DNA evidence that came in after I authorized additional DNA evidence to be collected, it was inconclusive so much so that we made this determination for an independent investigation."
But D.A. Anderson said scientific evidence shows that it's undeniable that Kevin Cooper's blood was found in several places. And he said Cooper's advocates haven't shown a shred of evidence indicating evidence was planted.
"It sounds like a neat little theory when someone says 'he was framed,' but given the opportunity to explain it, as has been done over the last 30 years, you find out there's nothing to this," Anderson said.
Furthermore, Anderson said even the theory that evidence was planted doesn't make sense.
"(To say) the prosecution planted Doug Ryen's blood and Kevin Cooper's blood on a T-shirt that they didn't introduce as an exhibit at trial, and were prescient enough to figure out in 20 years it would be tested by the defense, and then blood would show up and it would be a gotcha moment- that's absurd," he said.
It's unclear where the case goes from here, nor how long an independent investigation will take. But both sides are expected to be sitting down with an independent law firm that is reviewing the case.