Scott Peterson was arrested Friday morning in the slayings of his wife, Laci, and their son, Conner.
Several hours after his arrest in La Jolla, state Attorney General Bill Lockyer announced that DNA tests had positively identified the two bodies found earlier this week along San Francisco Bay as those of Laci and Conner Peterson.
Just before midnight Friday, Modesto police detectives arrived at the Stanislaus County Jail with Peterson, after driving him here from San Diego County.
Police had blocked off the street, and a crowd of about 200 waited outside the downtown jail. Many of them cheered as the police convoy drove up.
His arrest came nearly four months after his wife, 27 years old and eight months pregnant, disappeared from the couple's home in the La Loma neighborhood, setting off a media frenzy that captivated the nation.
Police Chief Roy Wasden, speaking at police headquarters Friday, would not discuss details of the investigation. He said there are no other suspects.
District Attorney Jim Brazelton said Peterson, 30, will be charged with two counts of murder, making it a capital case. Brazelton said he had not decided whether he will seek the death penalty.
Peterson's arraignment in Superior Court is likely to take place Monday or Tuesday.
His wife was reported missing Christmas Eve. He said he had gone fishing, alone, and she was gone when he came home.
Police searched his house twice, and seized his pickup and boat, but they never named him a suspect. Nor did they rule him out.
The arrest came at 11:10 a.m. Friday, even before police had received results of DNA tests that identified Peterson's wife and son as the woman and "full-term male child" whose bodies came ashore near Richmond.
"We've really tried for, hoped for, prayed for a different outcome than the one that has occurred," Wasden said. "While it's happy to have a conclusion, it's truly sad to have that conclusion."
The state lab made its determinations on the identifications shortly after 5 p.m. Friday. Agents with the state Department of Justice arrested Peterson earlier because law enforcement officials feared he might flee.
Lockyer, appearing on CNN's "Larry King Live," said officers had been following Peterson for a number of days -- and saw that "he was in San Diego, near the border."
Arrested near golf course
Agents arrested Peterson after pulling him over in a Mercedes-Benz that he was driving near Torrey Pines Golf Course in La Jolla.
Authorities declined to comment on the evidence against Peterson, but Lockyer offered his opinion on its totality.
"This is a compellingly strong case," he said. "I would call the odds slam-dunk that he is going to be convicted."
Peterson's attorney, Kirk McAllister of Modesto, could not be reached for comment.
Peterson's family, many of whom live in the San Diego area, also could not be reached.
Members of Laci Peterson's family asked for privacy and announced that they would make a public statement at 4 p.m. Monday.
Wasden and Lockyer held back-to-back news conferences Friday evening. Lockyer went first, at the state DNA lab in Richmond where technicians worked with bones and muscle tissue from the bodies that washed ashore, DNA samples from Laci Peterson's parents and a blood sample from Scott Peterson.
John Tonkyn, a supervisor at the lab, said it was "more than a billion times likely" that the woman's body was Peterson's. He gave a similar likelihood that the baby was hers and her husband's.
Then, at Modesto police headquarters, standing before cameras that sent his words across the country, Wasden announced Peterson's arrest.
Since late January, Peterson had mostly been keeping a low profile. But law enforcement had been keeping tabs on him. "Wiretaps on phones, tracking vehicles, all of the technology available," Lockyer said.
The attorney general revealed that police had attached a tracking device to Peterson's pickup. "We were careful about that information," Lockyer said.
Keeping that information secret was one reason police and prosecutors worked so hard -- successfully -- to keep all the search warrants sealed.
Peterson told police Dec. 24 that he last saw his wife at about 9:30 that morning, as he left for the Berkeley Marina and as she prepared to take their dog for a walk at East La Loma Park.
Peterson even provided a time-stamped receipt from the marina's boat launch ramp.
Search teams had worked the marina area, going north to Brooks Island where Peterson said he went fishing.
The bodies washed ashore a mile apart, in south Richmond and at Point Isabel, not far from Brooks Island. People walking along the shore came across the bodies, the baby's on Sunday and the woman's on Monday.
Causes of death had not been determined, said Contra Costa County Sheriff Warren Rupf, whose agency is handling the autopsies. He said the bodies appeared to have been submerged for "some time."
Police believe the killings occurred in Stanislaus County, Wasden said, but he would not go into detail.
Asked about a possible change of venue, Brazelton responded: "Where are you going to go to find somebody that hasn't heard about this case?"
At the outset, the nation saw Laci's and Scott's families united, attending news conferences together, pleading for the public's help in finding Peterson.
Then came a split, brought by the revelation of Scott Peterson's affair. Laci's family said he had denied an affair previously. But on Jan. 24, Amber Frey came forward to say that she had met Peterson on Nov. 20 and they had a romantic relationship. The Fresno-area woman said he had told her that he was not married.
Acknowledging the affair
Within a week, Peterson went on national television to acknowledge the affair and call it "inappropriate."
"It was not a positive, obviously but it was not something that we weren't dealing with," he told ABC's "Good Morning America."
He said he had told his wife about the affair and that she had made peace with it. "It wasn't anything that would break us apart."
The affair turned Laci Peterson's family against the son-in-law they had supported earlier. More strain came when he traded in his wife's Land Rover for a new truck. They begged him to cooperate with police, who had labeled him "uncooperative."
Peterson launched his own search effort, separate from the one organized by his wife's family. At one point, as searchers looked in San Francisco Bay and around Modesto, Peterson showed up in Los Angeles to distribute fliers at a hotel.
His own family stood behind him, with his mother, Jackie Peterson, the most vocal. She suggested that police had only one theory, that her son was guilty.
After Laci Peterson's due date came in mid-February, Jackie Peterson repeated her assertion that her daughter-in-law had been kidnapped by someone who wanted her baby.
Friday, calls and knocks at the door went unanswered at the Peterson home in Solana Beach, north of San Diego.
"This is a tragedy that is affecting many lives," Wasden said. "Lee and Jackie Peterson are Scott's parents, and they'll have to deal with that. They wanted to believe in their son, and they chose to do that. We went through with our investigation."
Peterson had kept mostly out of sight since his interviews with ABC and other news outlets in late January.
In February, though, he spoke with MSNBC, saying that he missed his wife and the child she was to bear.
"I can't drive. I can't sleep," he said then. "Sometimes I feel I just can't do it. I feel like I'm in a dark corner and I just can't function."
Bee staff writers John Coté and Patrick Giblin, and The Associated Press and Knight Ridder Newspapers contributed to this report.