All the Evidence That Convicted Scott Peterson of Double Murder

Scott Peterson’s trial for the murder of his wife, Laci Peterson, and their unborn son, who they had planned to name Conner, evoked a national reaction not unlike the O.J. Simpson case. When Peterson was convicted, cheers from an emotional crowd gathered outside were loud enough to reach the courtroom. However, it’s also a case where circumstantial evidence was king.

Scott told multiple people that he was headed to the golf course on Christmas Eve 2002. He also said Laci was going to walk their Golden Retriever, McKenzie, around the same time. By Scott’s account, it turned out to be too cold for golf so he decided to go fishing. He retrieved his 14-foot aluminum boat from a warehouse at his place of employment, drove 90 miles from Modesto to the San Francisco Bay area and spent about two hours fishing. 

When he got home, he noticed Laci’s car was in the driveway, but she was not around. After washing his clothes and showering, he called Laci’s mother, Sharon, at 5:17 p.m., asking if she was there. She wasn’t. Sharon suggested he call Laci’s friends. She found it peculiar that Scott said Laci was missing. Several rounds of calls later, the family went into panic mode. Sharon’s partner, Ron Gratski, called 911. 

Investigators needed to rule out as a suspect the last person who saw Laci, which happened to be Scott. “He just seemed like the perfect next door neighbor, perfect brother-in-law, perfect friend at the barbecue,” retired Modesto Police Department detective Jon Buehler tells A&E Crime + Investigation. The search expanded beyond Modesto to the Bay area. The initial search turned up nothing. 

Investigators soon learned that Scott was having an affair with Amber Frey, who thought he was single. Frey cooperated with police. Detectives started to notice Scott’s story had inconsistencies. Attorney Gloria Allred, who represented Frey, told NBC’s Dateline that Scott “lied and lied and lied and even lied about lying.”

In March 2003, detectives enlisted Gene Ralston and his wife, Sandy, retired environmental consultants who specialize in finding remains in bodies of water, in a renewed search of the Bay area. The couple used side-scan sonar to do sweeps of the ocean floor. Gene tells A&E Crime + Investigation that they found what he’s confident was Laci’s remains at Port Richmond. However, the weather was bad, and they didn’t have a recovery team, so they had to wait out the storm for a week. “By the time we went back with a suitable crew to do the recovery, she was gone,” Gene says. 

On April 13, 2003, a fetus was found floating a mile from where Scott said he went fishing. The following day, a torso washed ashore, also a mile away. The remains belonged to Conner and Laci, respectively. By then, Scott had changed his appearance: His hair was blond and he sported a goatee. Fearing he would flee, authorities arrested Scott on April 18. In his car, investigators found camping equipment, multiple cell phones, Scott's sister’s credit card, his brother's driver's license and nearly $15,000 in cash.

Prosecutions that rely on circumstantial evidence are hard to try. All the defense needed to do was create enough doubt for at least one juror to vote against a guilty verdict. “I was a bit concerned,” Allred told Dateline. “I felt that their burden of proving guilt beyond a reasonable doubt had not yet been met.”

The defense argued that Laci was seen around town walking McKenzie, so Scott couldn’t have disposed of the body during the time prosecutors claimed. Investigators discovered that three women, two of them pregnant, were walking dogs in the area the day Laci was missing. 

During the penalty phase, Scott’s lawyers suggested Laci was a victim of a satanic ritual, the fear of which had terrorized the nation during the 1980s and early 1990s. They also posited the scenario that Laci witnessed a home burglary, so the thieves kidnapped her with the intent of depositing her body in proximity to Scott. Modesto Police Department detective Al Brocchini told ABC News, “We pretty much dealt with all of the satanic cults, the dog walkers. The only thing we couldn't eliminate was Scott.”

Of the satanic cult theory, Phillip Stevens Jr., a professor at State University of New York at Buffalo told CNN, "I can't think Scott Peterson's lawyers are dumb. They've got to be aware of the credibility problems with this defense." 

Legal analysts argued that “the cumulative weight of all the circumstantial factors that pointed to Peterson—not least his alibi about going fishing in San Francisco Bay the day Laci Peterson disappeared from her home in Modesto...” was compelling.

On November 12, 2004, Scott was convicted of the first-degree murder of Laci and second-degree murder of Conner. A month later, he was sentenced to death. He was retried on the sentencing phase and got life in prison. 

The Los Angeles Innocence Project (LAIP), whose national brethren defends cases of people who say they were wrongfully convicted, filed a petition in April 2025 claiming false evidence was used to convict Scott. It argues that the new evidence warrants another trial. In its filing, LAIP said that “the prosecution’s theory of the case was based on conjecture and circumstantial evidence. There was absolutely no direct evidence supporting the prosecution’s case.” 

“Circumstantial evidence cases are frequently criticized by people outside the court, people outside of law enforcement,” Buehler says, “but premeditated murder isn’t usually gonna have a witness or video tapes. Premeditated murder is gonna be a circumstantial case most of the time.”

As of June 2026, all of Scott's motions—one for a new trial, one for a direct appeal, four requests for post-conviction DNA testing and two motions for post-conviction discovery—have been denied. His third petition for Writ of Habeas Corpus was also denied in April 2026, and at the same time, he withdrew a third motion for post-conviction discovery. When the third petition for Writ for Habeas Corpus was denied, a judge rejected all 14 claims in the Writ, which included the defense's accusations of suppressed evidence and claims of innocence, saying they were procedurally barred, lacking merit or both.