SAN FRANCISCO -- For a second time, a state appeals court in San Francisco Wednesday overruled Gov. Arnold Schwarzenegger and approved parole for a San Mateo man who killed his wife with a sledgehammer in 1986.

The Court of Appeal said the governor's decision to block parole granted by the state Board of Prison Terms to Peter George Cooper, 58, in 2006 did not meet the required minimum of having at least "some evidence" to justify the action.

A three-judge panel of the court unanimously said "there is no factual support whatsoever in the record before the governor to reverse the board's grant of parole to Cooper."

The same court made a similar decision in 2007 and Cooper was in fact released on Aug. 9, 2007.

This fall, the California Supreme Court ordered the appeals court to look at the case again under a slightly different standard. The panel today reaffirmed its previous conclusion.

Cooper, a computer programmer, was convicted in San Mateo County Superior Court of second-degree murder for killing his wife, Joan Harwitt, with a sledgehammer on Nov. 16, 1986, during an argument in which she berated him for being sexually inadequate while recovering from alcoholism.

He was sentenced to 16 years to life in prison.

In 2006, the parole board voted to release him, but five months later, Schwarzenegger blocked the parole under powers given to him in a voter-approved state constitutional amendment in 1988. Schwarzenegger said the brutality of the crime led him to conclude Cooper would be a public-safety risk if released.

The amendment allows the governor to overrule parole board decisions in cases of murders and others serving life prison terms if he finds the person unsuitable for parole.

The California Supreme Court upheld the measure in 2002, but said courts could review whether a governor's decision met a minimal standard of being based on at least "some evidence" that the parole applicant is currently a danger to society.

Last year, the high court refined the standard to say that the needed evidence can't be based solely on the facts of the original crime, if the crime was no more brutal than similar offenses and the prisoner appears to have been rehabilitated.

Under that standard, the appeals court said Cooper has been rehabilitated and shown remorse and there is an "absence of any evidence he is a current danger to society if released."

The ruling could be appealed to the state high court. Rachel Cameron, a spokeswoman for Schwarzenegger, said, "At this time, we are still reviewing the court's order."

Cooper's attorney, William Turner, said, "The court did the right thing."

State corrections department spokesman Gordon Hinkle said Cooper now lives in Daly City and will remain on parole until 2010.