CAUGHT WITH THE STRANDS OF DNA
Cracking cold cases the 21st century way — using a public genealogy database
John and Mei-lian Lin were having dinner and watching the news when the story broke that investigators had used a public genealogy database to help find the 72-year-old man they believe is the Golden State Killer, cracking one of California’s most notorious cold cases in decades.
John Lin dropped his fork. Then he picked up the phone.
With a direct line to Alameda County sheriff’s Detective Patrick Smyth, Lin asked if the same novel research technique could help solve the slaying of his 14-year-old daughter, Jenny. In 1994, she was stabbed to death in their Castro Valley home.
“It really boosted our hope that the sheriff could do the same thing and scale up the investigation of Jenny’s case, and hopefully we could get a break soon,” said Lin, who is 69 and retired and living with his wife in Los Angeles.
The Lins had reason to be optimistic.
In just over 10 weeks since Joseph DeAngelo was arrested on suspicion of a dozen slay-
ings and 45 rapes up and down the state during the 1970s and ’80s, law enforcement across the country has rushed to take advantage of the technology that links genetic profiles from crime scene DNA with family trees on a public genealogy website. Their success has been astounding.
At least five cold cases, each of which had stymied investigators for at least 25 years, have been solved using the new approach. In June, a 49-year-old disc jockey in Pennsylvania was blindsided when he was arrested in the 1992 killing of a Lancaster schoolteacher. In May, a truck driver in Washington state was arrested in the 1987 slaying of a young couple — the woman was raped and the man was strangled. And two weeks ago, a 59-yearold loner in Fort Wayne, Indiana, was nabbed in the 1988 rape and slaying of an 8-year-old girl. He immediately confessed.
Law enforcement’s quick success using the public genealogy database — originally created for people seeking distant relatives and building family trees — is ushering in a golden era for crime solving. Because none of the suspects’ DNA was in law enforcement databases, there had been no easy way to test them against samples found at the crime scenes.
“We’re at a watershed moment,” said Steve Armentrout, CEO and founder of Parabon NanoLabs, a Virginia company to which law enforcement agencies are sending their DNA samples, hoping for a match. “Cases are being solved at an unprecedented rate.”
Over the next year, he said, he wouldn’t be surprised if the technique helps solve at least 100 more cold cases.
In the Bay Area, San Mateo County is reviewing two cases, determining whether enough DNA remains from crime scenes to be good candidates. The Santa Clara County District Attorney’s Office is looking at five cold cases — a few of which have been sent to Parabon to run through the public database. It won’t say which cases.
“We are using the same technique, and we are using it because we wish to exhaust every method and effort we can to identify and prosecute killers,” said Matt Braker, Santa Clara County’s deputy district attorney in charge of the cold case unit.
Investigators aren’t counting on the suspected killers themselves to have uploaded their genetic profiles to the genealogy website. But, as in the case of the Golden State Killer, they’re hoping to find a distant relative’s DNA to help lead to a suspect who has lived under the radar for decades.
Although law enforcement
agencies are reluctant to discuss specifics, some are hoping the new approach can help finally track down two of the area’s most notorious cases: the Zodiac Killer and the NorCal rapist.
San Francisco police say that for now, they are not using the technique. But in Vallejo, where the Zodiac Killer also claimed victims in the late 1960s, police have sent envelopes of the Zodiac’s DNA — from licked stamps he put on taunting letters to police and newspapers — to a private lab for review. In Contra Costa County, where former forensics chief Paul Holes pioneered the technique to track down the Golden State Killer, officials at the District Attorney’s Office are unaware of other cold cases using the same approach.
But what about Alameda County, where Jenny Lin was killed?
Authorities there say that while the Jenny Lin case continues to be a top priority, they are hesitant to use the genealogy database, citing issues raised by the ACLU and other groups that mining “deeply private and sensitive” genetic codes violates privacy rights of the perpetrators as well as innocent, distant relatives.
“There’s a lot of uncharted waters, legal, moral issues that have been brought up in regards to this. There are some naysayers saying doing this is too intrusive. So we don’t know where this is headed,” said Alameda County sheriff’s Sgt. Ray Kelly. “We’re not saying we would never do it, but we would do it with a court order or search warrant.”
It’s the last thing the Lins want to hear.
“That certainly makes me wonder if they are too conservative and overly protective of certain parts of the investigation,” said John Lin, who has gone through three detectives assigned in the 24 years since his daughter’s slaying. “From the victim’s family’s
point of view, I would certainly prefer they could take a more aggressive approach to help us solve Jenny’s case.”
They’ve waited so long. In 1994, the Friday before Memorial Day weekend, Lin came home from work just before 7 p.m. to find his teenage daughter stabbed to death in the bathroom.
“Immediately I came into a nightmare, an endless nightmare,” he said. “I still feel like I’m in a bad dream and can’t wake up.”
He hasn’t given up. The Jenny Lin Foundation is active, the $100,000 reward for information still available. The family holds regular vigils and, on Friday, traveled from their home in Los Angeles to co-host a youth music concert at Chabot College in her memory.
“Until this case is solved, there’s no peace,” John Lin said. “I promised my daughter Jenny I would solve this case before I will take a rest.”
Not all cases are good candidates for using the “genetic genealogy” approach. The DNA must be of enough quantity and quality to get a strong genetic code. Lack of strong DNA has been a chronic problem in solving the Zodiac Killer case, in particular. Saliva from the stamps he licked in sending taunting letters to law enforcement and newspapers is weak, investigators have said.
Genetic profiles that are being accessed by law enforcement come from public, open-source genealogy databases such as GED-match. They usually start with a “spit kit” people submit to “recreational genomics companies” such as Ancestry.com and 23andMe, with hopes of matching their DNA with distant relatives. Those two companies are off-limits to law enforcement without court orders. But customers are allowed to take their own genetic profiles produced from those companies and are uploading them to GED-match, hoping that other relatives might find them.
“We’re just using those people who said, here I am, please search,” said Holes, the former Contra Costa County forensics chief who helped a statewide team track down the Golden State Killer.
A hit on the database to a third cousin of DeAngelo’s was only the first step, however. Holes used that discovery to search the cousin’s family tree for relatives who were a closer match to the killer’s profile. Then investigators had to conduct some good old-fashioned police work. With evidence from crime scenes and witnesses, they knew they were looking for someone who was likely in his late 60s or early 70s, who had lived in different parts of the state during certain years and — in the Golden State Killer’s case, in particular — someone who was involved with a woman named “Bonnie” in his past. He had yelled out her name to some of his victims. DeAngelo, who lived outside Sacramento, had once been engaged to a woman named Bonnie.
Investigators secretly followed DeAngelo for days. When he discarded something smeared with his DNA — police wouldn’t say what — they matched it to DNA from one of the crime scenes.
Holes retired just days before the arrest but still has been inundated with calls from law enforcement agencies across the country asking for advice to pursue the same tactic.
It isn’t foolproof. “We don’t want to lead families of other homicide victims to think this is a magical technique that will solve every case. It is not,” said Brett Hambright, a spokesman for the Lancaster, Pennsylvania, District Attorney’s Office, which used the technique to arrest Raymond Rowe in the 25-year-old cold case slaying of schoolteacher Christy Mirack. “And we were up front with the Mirack family about that when we started this process.
There are certainly no guarantees.”
Lancaster police had exhausted all leads. The evidence included semen, but it didn’t match any DNA in the federal database of known criminals. But when Parabon ran the sample through the GEDmatch database, investigators were stunned. The results pointed to a local DJ who lived 4 miles from Mirack’s home at the time but had never been known to police.
Investigators staked out the DJ during a gig at an elementary school and obtained a “surreptitious sample” of his DNA — chewing gum and a water bottle he had tossed. That DNA matched the semen sample from the crime scene, investigators said. Rowe was promptly arrested.
With 160 DNA samples from law enforcement agencies across the country, Parabon is working on 50 cases. Not every sample matches someone in the million-sample-strong GEDmatch database — its hit rate is about 50 percent. But when matches are made, Parabon has either identified the killer or gotten as close as a brother or son, Armentrout said. Local law enforcement, using traditional investigative techniques, does the rest.
Like the Lins, families of other cold case victims are pressuring law enforcement to try genetic genealogy on their cases. About a half dozen families have contacted the Santa Clara County District Attorney’s Office in recent weeks.
Braker, in charge of the cold case unit there, said that while he has considered the privacy issues that are holding up Alameda County, “those things are going to work their way through the legal system.”
“To me, weighing the balance and finding the killer, I think we should exert these efforts,” he said.
With so much time passed, however, some victims’ family members are weary about digging up the trauma. Robert Stitt said he was told by Sunnyvale police years ago that they had a “blood drop” from his daughter’s killer. In 1982, Karen Stitt, a Palo Alto High student, was found near a Sunnyvale bus stop naked and bound and stabbed 60 times. Whether there is enough DNA to provide a potential match in her case is unclear.
Unlike the Lin family, Robert Stitt has mixed feelings about any renewed push to find the killer. He still lives in Palo Alto, but he is 77 now and disabled by a heart condition.
“The whole thing is so painful for me,” he said in a recent phone interview. “I don’t know whether I can handle a lot of attention being paid to this. I’m not sure I could handle a trial.”
He hasn’t heard from law enforcement in about a decade.
For John Lin, however, no matter how he might try, he can’t stop thinking about his daughter’s slaying.
“When we wake up in the morning, the first thing we think about is Jenny’s case,” he said, “and it’s the last thing we think about when we go to bed.”
By keeping Jenny Lin’s story in the limelight — like hosting Friday’s concert in her memory — he’s hoping that old-fashioned investigation techniques will come through. Maybe a witness will remember something, or an acquaintance of the killer will come forward.
“We want the public to know,” he said, “that until Jenny’s case is solved, there’s still that monster out there.”