Scott Peterson

Scott Peterson, flanked by defense attorneys Mark Geragos, left, and Pat Harris, sits during his 2004 trial for the 2002 murders of his pregnant wife and unborn son. Peterson was convicted and sentenced to the death penalty. He appealed the sentence this week, saying the trial had been tainted by overwhelming publicity and a biased jury. (Al Golub, Associated Press / July 7, 2012)

Convicted murderer Scott Peterson told the California Supreme Court that his guilty verdict and death sentence should be overturned because his trial was tainted by massive publicity, a biased juror pool and shaky evidence.

Peterson, condemned to die for killing his pregnant wife Laci and their unborn son in 2002, said in his 427-page appeal that prosecutors had no evidence of how, where or when Laci was killed, and that overwhelming pretrial publicity had infected the juror pool and the trial.

"The case against Mr. Peterson was anything but overwhelming," Cliff Gardner, Peterson's lead lawyer, argued in the appeal that is automatically granted to capital murder convicts. "There were no eyewitnesses, no confessions, no admissions and scant physical evidence connected him to the crime."

Nearly half the prospective jurors said in pretrial questioning they believed the Modesto fertilizer salesman killed his wife, and a billboard outside the courthouse asked people to call in and vote on whether Peterson was "man or monster," said the appeal, filed Thursday.

Public sentiment was so inflamed against Peterson that police feared he might be lynched when he was arrested, according to his appeal. His lawyers at the time feared he could not get a fair trial and asked that the case be moved from Stanislaus County to Los Angeles County. A judge decided instead to send the case to San Mateo County, about 90 miles from Modesto.

Peterson's legal team reminded the court that "a mob" of more than 1,000 people waited outside the San Mateo County courthouse for the verdict and wildly cheered the departing jurors after they had found Peterson guilty but before they had deliberated whether he should be condemned too die.

Laci Peterson, eight months pregnant, disappeared on Christmas Eve 2002. Peterson told police he had gone fishing in San Francisco Bay off the Berkeley Marina that day and returned to find their Modesto home empty.

Intensive searches failed to find a trace of the missing woman until the remains of her unborn son, Conner, washed ashore in Richmond, just north of Berkeley, in April 2003. Laci's remains were found nearby the next day. Medical experts said decomposition had probably released the fetus from the mother.

Peterson noted in his appeal that he had no criminal record or history of domestic violence. Family and friends had said they believed the Peterson marriage was strong, though Peterson was discovered to have been having an affair with a massage therapist when Laci disappeared.

Prosecutors theorized that Peterson either smothered or strangled his wife on the evening of Dec. 23 or early Dec. 24, 2002. Several searches of the Modesto home failed to find evidence of blood or tissue.

Peterson's lawyers argued in the appeal that the trial judge improperly excused all jurors who said they opposed the death penalty but would consider it an option, producing a jury that unfairly tilted toward the prosecution.

They also complained that the judge permitted expert testimony about the movement of bodies in water even though the so-called expert admitted he was not schooled in the subject. The judge also allowed "highly prejudicial dog scent evidence" even though the dog had a record of being wrong 66% of the time, the appeal said.

"The evidence the state claimed conclusively established Scott's guilt was simply unreliable and should never have been admitted in this capital trial," Gardner wrote.

All death row inmates are entitled to an "automatic" appeal that goes straight to the state's highest court. Peterson's case is unlikely to be resolved for many months, even years. More briefs will be filed, and the court could spend a year or more studying the written arguments before scheduling a hearing.

Peterson also is entitled to file a second legal challenge based on evidence that was not presented at trial and may appeal his case in federal court if he loses before the state court.