The mystery began to take shape four years ago when scientists at the Orange County Sheriff's Department's DNA lab started applying new technology to old murder cases and found three with striking similarities.
The next year, the department's new "cold case" unit found evidence that a previously undetected serial killer may have left at least 10 victims in three Southern California counties from 1979 to 1986.
On Monday, investigators revealed that they have been silently tracking a man who carefully picked his victims from upscale communities in Orange, Santa Barbara and Ventura counties and who now could be dead, in prison or still on the loose.
DNA tests of semen and hair found at four crime scenes and a common method have led investigators to believe that a single man was involved in six different attacks.
The idea that the killer may still be alive has spurred Orange County Sheriff's Det. Larry Pool to conduct a desperate search to match a face to the trail of DNA.
But after years of reviewing hundreds of sexual assault cases and a trip to San Quentin's death row, Pool said Monday that the killer's identity remains a mystery.
"This is the kind of case that wakes me up at 3 in the morning because a person with this kind of desire, this kind of murder driven by fantasy, these people can't stop," Pool said. "The only thing that will stop them is something beyond their control, like death."
Pool explained the stakes of his investigation. "He could be in prison and for all we know get out tomorrow," he said. "And then he'll do it again."
The killer has left some broad clues. He is believed to be white. Sometimes he brought a German shepherd with him. Officials guess he was living in the Goleta area of Santa Barbara County when he surfaced.
Authorities say the series of crimes began in the fall of 1979. Abraham Himmel and Jennifer Horinek, both 33-year-old computer programmers, survived an attack in their Goleta home.
Himmel and Horinek were awakened at 2 a.m. when a young man shined a flashlight in their faces and commanded, "Wake up! Wake up!" The man seemed to talk through clenched teeth, telling them not to move or he would kill them, the couple said. "I gotta have money. I'll kill you. . . . Don't move or turn your head."
Before the assailant could carry out his threat, Horinek managed to flee into a side yard, allowing Himmel to escape.
It was described by investigators as "a practice murder" and was the first of three attacks over 18 months in the same neighborhood. Six people were assaulted in their bedrooms and four were killed.
The man apparently struck again Dec. 30, 1979. Dr. Robert Offerman, an osteopathic surgeon, and Alexandria Manning, a clinical psychologist, were killed after their hands were tied behind them with twine.
The killer, who brought a dog with him, entered Offerman's condominium through a sliding glass door while Offerman and Manning were asleep in their bedroom.
Nineteen months later, Cheri Domingo, 35, a corporate manager, and Gregory Sanchez, 27, a Burroughs Corp. employee, were killed in Domingo's home about half a mile from Offerman's condo.
He was shot in bed and bludgeoned. He had not been tied up; her hands were tied behind her back and she died of massive cerebral injuries.
At the time, detectives believed that the Goleta murders were random. There was no evidence of a sexual motive, but the joint task force investigating the killings said that Santa Barbara investigators did not collect the kind of evidence that could be tested for DNA.
However, Santa Barbara County sheriff's investigators told The Times in 1981 that they thought the Goleta killings were linked to two in Ventura and two more in Laguna Niguel, both in 1980.
In the Ventura case, Lyman Smith, 43, a prominent attorney, and his 33-year-old wife, Charlene, a court clerk, were bludgeoned to death with a fireplace log in their Ventura home.
Smith's appointment as a judge was expected within days. He was chairman of the county's Democratic Central Committee. He and his wife were slain in their bed about midnight March 13, 1980.
A business associate, Joseph Alsip, was charged with murder but eventually freed. Task force investigators eliminated Alsip as a suspect based on DNA evidence.
"The big problem is we don't know whose DNA it is," said Dist. Atty. Michael Bradbury, who was the prosecutor in the case. "But a greater database is being built daily, so I hope this one will be solved. But it's one of those that continue to haunt me."
About five months after the Smith killings--on Aug. 19, 1980--officials now believe that the killer struck in Orange County for the first time.
Keith Harrington, 24, a fourth-year UC Irvine medical student, and Patrice Harrington, 27, a pediatric nurse, were found in the bedroom of their fashionable Niguel Shores home.
The newlyweds had been beaten to death with a blunt instrument, police said. Their bodies were found when Harrington's father stopped by the house the next morning.