The investigation into the suspected homicides of a San Marino couple is now focusing on a large bloodstain that detectives discovered in the couple's guesthouse in 1994, when human remains were dug up in the backyard.
Authorities have described a man now under arrest on unrelated kidnapping charges in Boston as a "person of interest" in the disappearance and suspected killings of Jonathan and Linda Sohus, who were last seen in 1985.
Los Angeles County Sheriff's Department detectives claim that the Boston man, Clark Rockefeller, used to be known as Christopher Chichester and lived in the couple's guesthouse at the time they disappeared.
The bloodstain is another tantalizing clue in what authorities believe was a murder or murders on the Lorain Road property more than two decades ago.
But authorities acknowledged that linking this and other forensic evidence to the killer will be difficult. In fact, officials have been frustrated as various leads have turned into dead-ends.
Tricia Gough, a former San Marino detective who worked the case in 1994, said the bloody stain was not clear to the naked eye. But when investigators sprayed a blood indicator on an area of the guesthouse floor it became clearly visible.
Detectives tried but could not determine the blood's source.
Sheriff's Department spokesman Steve Whitmore said officials will now be reexamining the blood using more advanced technology.
Detectives have long believed the remains are those of Jonathan Sohus. But they have been hampered by the fact that Sohus was adopted, and, so far, investigators have not been able to match the DNA to a relative to prove the skeleton's identity. Authorities said Wednesday they will complete a new round of DNA tests on the remains.
Marks on the skull suggest that the person suffered a potentially fatal blunt-force trauma, but officials acknowledge that they cannot provide a specific cause of death.
The skeleton was found by workers digging a pool for the new owners of the home. Gough said the remains were wrapped in several small plastic bags tied together with twine.
"It was a rush job. The person was in a hurry. The skeleton was wrapped like a mummy in the plastic bags, the kind you get from Vons," Gough said. "It was like if you or I were to commit a murder and said, 'Oh my goodness, what have we done?' We believed it was Jon Sohus. There were physical similarities."
Investigators determined that the body had not been in the ground for more than a decade or so because it was clothed in jeans, a flannel shirt and tube socks, she said.
Dental records turned into another dead end.
Gough said she tracked down the Pasadena dentist's office where Jonathan Sohus had been a patient but the dentist had retired and Sohus' records apparently were lost.
Marc Taylor, president of the private Ventura-based DNA testing facility Technical Associates Inc., said even blood found more than a decade ago can yield DNA evidence.
"It depends on the surface where the blood was," he said. "If the evidence was placed in a police vault, and if it is packaged right, you have a very good chance of getting DNA."
Even a small sample can result in a match, he added.
But Taylor said police have a bigger problem to deal with: finding a match from the blood to Sohus.
Investigators could try to overcome that by finding an envelope Sohus may have sent to someone and sealed with his saliva, Taylor said.
County coroner's chief Ed Winter said homicide detectives had placed a security hold on the case Wednesday and that he was no longer able to provide details about the remains.
In Boston, Rockefeller's attorney, Stephen Hrones, has repeatedly denied that his client had anything to do with the couple's disappearance, telling the Associated Press on Monday that Rockefeller barely knew the Sohuses while living on their property.
Investigators were able to identify Rockefeller as the man who lived in the guesthouse through numerous interviews with people who contacted authorities, Whitmore said.
Police on both the East and West coasts had been investigating Rockefeller, who is accused of absconding from Boston with his young daughter and was captured Aug. 2 by the FBI in Baltimore.
Ellen Sohus, Jonathan's stepsister, said in an interview with The Times that she has long believed that her brother was murdered on the property sometime in 1985.
"I believe he was murdered in the guesthouse, then buried in the backyard," she said. "I wish I knew. It makes no sense to me."
Times staff writer Molly Hennessy-Fiske contributed to this report.