(Newser) – Now that California has lifted its moratorium on the death penalty, convicted murderer Kevin Cooper, 57, is once again preparing to be executed for high-profile slayings he says he didn't commit. "I am innocent," Cooper tells NBC News. "And it's not my execution, it's my murder." Cooper has been on death row since 1985, when he was convicted of the brutal 1983 slayings of Doug and Peggy Ryen, their 10-year-old daughter, and another child who was spending the night in their Chino Hills, Calif., home. The Ryens' 8-year-old son, left for dead with a slit throat, survived. He initially told police that three white or Latino men committed the murders but has since come to believe that Cooper was the lone killer. Prosecutors say Cooper, who had escaped from a nearby prison the previous night, had been hiding out in a house near the Ryen home. Wielding a hatchet, ice pick, and one or more knives, they say he slaughtered the victims and drove away in their station wagon.

Cooper has maintained his innocence throughout, and there are plenty of people who believe him, saying police withheld information, ignored other suspects, and tampered with evidence, particularly blood samples. In 2004, Cooper was three hours away from being put to death when a federal appeals court stopped the execution, deciding some of the evidence was flawed. "You watch the clock as your life goes off," he says, "minute by minute." Nonetheless, many others say Cooper is guilty, even former defense team members, writes San Francisco Chronicle columnist Debra Saunders. To think otherwise is "utterly unreasonable," the California Supreme Court ruled in 1991. Cooper's conviction was upheld in 2009, keeping him on death row. Now, Cooper tells NBC, he is appealing to California Gov. Jerry Brown to have "an open mind" about the evidence in his case and intervene. (Read more California stories.)

