How family tree DNA databases are helping to crack cold cases
When Chelsea Rusted joined Ancestry.com and submitted a DNA sample to match with long lost relatives, little did she know it would help police solve a double murder. And she’s not alone.
Chelsea Rustad was sitting in her home in Washington state in 2018 watching TV with her fiancé when she heard a knock on her front door. To her surprise, two police officers were standing there. “I was just so confused,’’ she says. “Mostly about why there would be police on my doorstep wanting to talk to me for any reason.’’ The officers gently explained that one of her distant relatives was suspected of committing a horrific double murder long ago – and that after fruitless investigations spanning three decades, Rustad was the key to his identification.
Five years earlier, Rustad had bought an Ancestry.com subscription and started building her family tree. In 2015 she got an Ancestry home DNA test kit and submitted a saliva sample for testing. When the results came back she uploaded the raw data file to GEDmatch, an online database that allows people to share and compare their DNA to find relatives who have used different testing companies. Rustad didn’t find much of interest and promptly forgot about the site and her input to it. But that simple act would inadvertently lead police to the man they believed killed Canadians Jay Cook, 20, and his girlfriend Tanya Van Cuylenborg, 18, on a trip to Seattle in 1987.
Van Cuylenborg had been raped and shot in the back of the head at close range. Cook had been strangled, and was found with a packet of cigarettes stuffed down his throat. For 31 years, their families had no answers. Then came the game changer. In 2018 a new investigative technique called forensic genetic genealogy was used to identify former cop Joseph DeAngelo as the notorious Golden State Killer, responsible for at least 13 murders, 50 rapes and 120 burglaries across California in the ’70s and ’80s.
The technique involves police uploading DNA profiles from crime scenes to public databases in the hope of identifying close or distant relatives that may lead back to a suspect. DeAngelo’s arrest was, for investigators searching for new leads on the Cook and Van Cuylenborg murders, a “light bulb moment”. They brought in a specialist DNA firm and genetic genealogist CeCe Moore to see if the method could work on their own cold case. Semen had been recovered from Van Cuylenborg’s pants and body, but there had never been a match despite various suspects over the years and ongoing checks on the FBI’s national offender DNA database. For the first time, the investigators arranged for the DNA profile to be uploaded to public database GEDmatch.
Major DNA testing companies including Ancestry have privacy policies restricting law enforcement’s use of their vast databases – but on GEDmatch at that time there was nothing to stop police searching for relatives. How closely people on the site are related is initially predicted through the amount of DNA they share. The search turned up two second cousins of the killer. Chelsea Rustad was one.
Moore started building a family tree for Rustad and the other cousin and found her prime suspect: William Earl Talbott II. It was Moore’s first criminal case and it had taken her just two hours to produce a name that had never before appeared in the investigation. Incredulous police put Talbott under surveillance. When a paper coffee cup fell from his truck, it was covertly seized and analysed, confirming a direct DNA match to the semen from the murder scene. After all those years of searching, an ingenious forensic technique had provided answers in less than the time it takes to watch the average Hollywood blockbuster.
Rustad was initially bewildered as the two police officers at her home tried to explain these events. “It was such a novel technique at that time,” she says. “It wasn’t really widely known that this was a method for solving cases. They explained to me what was going on, but then I just had even more questions. It was kind of dumbfounding to realise that, unknowingly, I had played a role in the identification of this man who committed these terrible acts decades ago.”
Rustad now proudly calls herself a “genetic witness” and says it felt “kind of cathartic and a little empowering” to help the victims’ families. “But first, I kind of had to get past that initial shock, because there’s also a little bit of shame attached to it. The suspect was a second cousin I’d never met. I didn’t have any strong family attachment to this guy because I didn’t know him at all. But you still feel like there’s some type of intrinsic connection to him.”
Now, Rustad’s experience could be replicated inAustralia. Federal and NSW police announced last October that they were assessing the technique of forensic genetic genealogy for its use here. Its potential to solve crimes is significant. So too, it seems, are the possible ramifications for the many Australians who have taken an at-home DNA test, available for less than $100 and commonly given as birthday gifts.
Worldwide, more than 40 million people have swabbed their mouth or sent off a sample of saliva to DNA companies to explore their ancestry, health and inherited traits. If police were able to tap into those results it would offer a new way to identify offenders who were never going to be found through traditional testing on limited government DNA databases.
In Australia, the National Criminal Investigation DNA Database has more than 1.2 million DNA profiles uploaded from convicted offenders, suspects, volunteers, missing persons, unknown deceased and crime scenes across the country. Searching separate, public databases opens up potential matching to a wider group of people: those who have done at-home consumer DNA tests and who may never have had a reason to end up on a government database. And by looking at a greater number of genetic markers, it allows matching to far more distant relatives.
There are some key limitations. The largest genealogy firms that offer at-home DNA tests still bar law enforcement from accessing their DNA databases. That leaves, primarily, two databases police can (and do) use. One is GEDmatch. The other is FamilyTreeDNA, a pioneer of consumer DNA testing that has more than a million genetic profiles; it allows police to search them unless customers opt out. Last year, along with parent company Gene by Gene, it merged with Australian genomics company myDNA.
GEDmatch, after fierce debates about privacy and ethics following the Golden State Killer arrest and the cases that followed, opted all of its users out of law enforcement searches; people must now opt in to make their profiles available to criminal investigations. It was bought by forensic genomics company Verogen in December 2019 and holds about 1.45 million DNA profiles.
Both GEDmatch and FamilyTreeDNA only allow law enforcement matching for violent crimes and to identify human remains, and police do not get the genetic information on the databases – all they can see is who the unknown suspect or deceased is related to, and how closely. It’s then a matter of using available records such as obituaries, newspaper archives and social media to build family trees. Most people on genealogy databases have European ancestry, making the technique less effective for people of other backgrounds. While some cases are solved quickly, such as the Cook and Van Cuylenborg murders, others take many months of painstaking research.
Still, it has officials such as Australian Federal Police research and innovation co-ordinator Dr Nathan Scudder asking if it will be possible, with enough time and effort, to identify almost any suspect from recovered DNA. Scudder and two NSW Police Force experts last year completed a forensic genetic genealogy course at the University of New Haven in the US to learn more about the technique. “It’s an exciting area, but we have to get it right,” Scudder says. “We have to ensure that when we use it, the community is comfortable with the safeguards that are in place.”
The Golden State Killer broke into homes, sometimes naked from the waist down, sexually assaulting women and attacking couples. Police had his DNA from crime scenes but could never find a match. Joseph DeAngelo escaped the police dragnet for more than 40 years and was living comfortably in retirement in suburban California, a husband and father of three daughters, when his family tree finally gave him away. Investigators and a civilian genealogist, Barbara Rae-Venter, made the breakthrough in 2018 using DNA from semen recovered from a 1980 double murder. According to the Los Angeles Times, they conducted covert searches on not only GEDmatch and FamilyTreeDNA, but also on MyHeritage – which allows uploads from other providers. (MyHeritage has since updated its privacy policy to make it clear law enforcement use of its DNA services is prohibited.) Once they’d discovered relatives, investigators built a family tree that led them to DeAngelo. A tissue covertly collected from a bin outside his house confirmed a DNA match to the semen from the 1980 crime scene.
The same technique has since resolved more than 250 US cases – identifying criminal suspects and the remains of long-term missing people. In Sweden, it led to the arrest in 2020 of a man for one of the country’s most infamous crimes, the stabbing murders 16 years earlier of an eight-year-old boy as he walked to school and a woman who witnessed the slaying. The killer was convicted and sentenced to psychiatric care indefinitely.
In Australia, authorities have been much more cautious about adopting the technology. “You don’t get a second chance to demonstrate to the public that a new technique is proportionate, that the use is compliant with privacy requirements,” says Scudder. “It’s really important to do that work up-front.” However, there is one known instance where it has been used here. Working with the approval of coroners and the assistance of an international expert, Victorian scientists have for the past two years trialled the technique to identify human remains in cases where all else failed. They believe it has given them the leads to finally identify two people. A separate AFP program has also been cleared to use the technique to solve unidentified human remains cases. “We’re working through a lot of the legal and privacy issues around criminal use,” says Scudder. “But certainly, human remains identification is easier – there are less privacy considerations, and hence it’s an area where there is a high level of public support. That’s realistically the first cab off the rank here.”
In late 2019, Dadna Hartman travelled to Melbourne’s Parkville biomedical precinct in a taxi, her hands firmly gripping a small esky. Most people worry about leaving a phone or laptop behind in a cab. Hartman, chief molecular biologist at the Victorian Institute of Forensic Medicine, had far more precious cargo.
Inside the esky, stored on ice, were 24 test tubes, each labelled with an identifying barcode. Some were control samples; others contained DNA extracted from seven sets of unidentified human remains. Hartman was hand-delivering the samples to a trusted testing facility. In doing so, she was taking some of the first tentative steps in Australia towards the use of forensic genetic genealogy. She knew the technique was being used to spectacular effect in the US, but would it work on some of the institute’s long-term unidentified cases?
When a person is found dead and can’t be identified, attempts are made to find a match to relatives who have provided DNA specifically for the purpose of finding family members. “That’s reliant on having the appropriate reference samples,” Hartman says. “When we don’t, and we upload our unidentified human remains profile [to government databases], there’s no matching data. From a DNA point of view, that’s as far as we can take it using the current analysis pipeline.”
Forensic genetic genealogy offers a way forward, but it’s not as straightforward as it may seem. Authorities can’t just take standard DNA profiles generated by government laboratories and upload them to ancestry sites. These routine forensic profiles look at a relatively limited number of about 20 DNA markers that will link only to a direct match or immediate family members – parents, children or siblings. By contrast, profiles generated by commercial genealogy companies look at hundreds of thousands of markers, enabling matches to a much larger pool of distant relatives. Authorities need to develop compatible profiles for comparison, but at present government labs don’t have the capability. So samples must be sent to private facilities where DNA data is developed and sent back. That’s how Hartman ended up in a cab delivering 24 test tubes of genetic material to the Australian Genome Research Facility. It would develop the DNA data needed to enable her to look for broader relative matches on a public ancestry database.
When the data arrived back at the institute via a secure portal, it was refined and uploaded to GEDmatch as a profile suitable for searching. About 24 hours later, they had their first results. One of the cases showed strong matching to relatives including potential second cousins. It was a start. “We were huddled in my office looking at the results coming through, very excited that we had some data to work with,” Hartman says.
Retesting some of the DNA samples and an additional one, the scientists ran the data through GEDmatch again. This time a second case showed good hits to close relatives. From these two promising cases, one was selected for uploading to FamilyTreeDNA, where the Victorian scientists struck gold – a first cousin. American genealogist Colleen Fitzpatrick, from Identifinders International, then came on board to help build the family trees. It’s now up to a coroner to decide if these investigative leads have identified the remains. “We’ve been working on these cases for many, many, many years,” Hartman says. “I feel personally that I have a duty to these cases to try and give them a name, to find out who these individuals are and reunite them with their families. Even if it takes us all this effort, it’s our purpose.”
Fitzpatrick was the first person in the world to use genetic genealogy in a criminal case. Back in 2011, she compared a DNA profile from the 1991 rape and murder of a 16-year-old girl, Sarah Yarborough, to others in genealogy databases. It turned up a match through the Y-DNA of the male line to the Fuller family, whose relatives had been on the Mayflower, the ship that delivered a group of English families to the shores of America in 1620. Police went public, and the backlash was swift. “At that point, I was the most hated person in the genealogy world,” Fitzpatrick says. “The genealogists exploded and panicked. They were saying that big brother had their DNA, and now everybody was gonna be arrested and interrogated and the DNA people were gonna be subpoenaed into court. I mean, I was using public data. It was all right there on the internet.”
Yarborough’s killer remained unknown at the time. The case came full circle in 2019 when advances in DNA testing allowed Fitzpatrick to generate leads that led to the arrest of Yarborough’s accused killer, Patrick Nicholas, then 55. He had a different surname than she initially expected because his grandfather had been adopted.
In 2018, weeks before the Golden State Killer arrest, it was announced Fitzpatrick and her co-founder of the non-profit DNA Doe Project (it has long been customary to name unidentified human remains “John Doe” or “Jane Doe”) had used GEDmatch to discover the identity of a young woman found dead beside an Ohio road in 1981. Strangled and beaten, she became known as the Buckskin Girl because of her distinctive buckskin poncho. A GEDmatch search showed a match to a close cousin, and led to the discovery of an online family tree that included a relative, Marcia King, as “missing – assumed dead”. It had taken just four hours of searching to solve a 37-year mystery.
The case didn’t get a lot of publicity. “Then you have the most monstrous serial killer in the world caught with the same technique,” Fitzpatrick says. “That’s different. You’re gonna get a lot of headlines. And that’s what started the present revolution.”
Monash University’s ethical, legal and social adviser in public health genomics, Jane Tiller, says people don’t always consider the implications when, for example, they consent to uploading private details to a public website. So there’s a risk of some people being very surprised if police turn up asking about relatives. Also, opt-in and opt-out arrangements and privacy policies may not always stop law enforcement from accessing information. “If you opt out and there is a court order to GEDmatch to hand over data, it’s hard to refuse that,” Tiller says. “If a court order compels a company to hand over data, they end up with big consequences if they continue to resist that.”
As evaluations continue, Australian police are increasingly conducting familial DNA searches of state and national crime databases for serious unsolved offences. They are looking for close relatives when no direct matches can be found to DNA recovered from crime scenes. It was first used successfully by South Australian police to catch a man dubbed the North Adelaide Rapist in 2015. In that instance, police had a DNA profile from two different sexual assaults but no direct match. Familial searching generated a list of potential relatives and eventually led to the identification of Patrick Perkins as the offender. He had been caught because a close family member’s DNA was on a government database.
Familial DNA analysis was also used in Cooktown, Far North Queensland, after the body of local mother Donna Steele was found wrapped in a doona and weighed down with rocks in a remote creek in 2017. Police snipers were flown in from Brisbane to stand guard against croc attacks while divers did a fingertip search for evidence. Among the items recovered was a piece of red twine identical to the one used to bind Steele’s hands. It bore the DNA of an unknown person. Suspecting the killer was a local, police asked residents to submit their DNA. Among those who did was the mother of Matthew Ross White. She was found to be a familial match to the DNA recovered from the twine, leading to the arrest of her son, 25, who confessed.
In January, NSW Police revealed that in the previous two years familial DNA searching of government databases had given new leads in 15 homicides, 18 rapes, 16 robberies, 35 break and enters, three kidnappings and 19 other crimes. Contributing to these results was the state’s embrace of Y-STR analysis, allowing them to trace more distant male family members by focusing on the male Y chromosome. Y-STR analysis is particularly useful in sexual assaults, due to its ability to detect tiny amounts of male DNA in mixed profiles that might otherwise be masked by female DNA.
“We’ve had this capability for a while,” NSW Police forensic evidence research co-ordinator Dr Jennifer Raymond says of familial searching. “But it’s now being used much more extensively. So the chances of getting good results just using normal techniques is increasing, even without having to resort to forensic genetic genealogy when there’s absolutely nothing left to go on.”
An audit by the AFP’s National DNA Program for Unidentified and Missing Persons last year found 850 sets of unidentified human remains were stored in police and forensic facilities across the country. The program’s dedicated laboratory has been operational since September. Dr Jodie Ward, the program’s head, says a full privacy impact assessment has just been completed that will allow a raft of new forensic techniques to be applied to chosen cases. “That has now been endorsed by the AFP, so we are now in a position to start performing forensic genetic genealogy on suitable unidentified human remains cases,” Ward says.
Chelsea Rustad has no regrets about her DNAtest. Her second cousin, Talbott, became the first person to be convicted of murder on genetic genealogy evidence. She went to his sentencing to support the victims’ families and wrote a book, Inherited Secrets. (In December, the conviction was overturned due to juror bias; his DNA match has not been challenged.) “It feels like this is a new and powerful and effective way for people to contribute towards families getting answers and getting justice,” Rustad says. “If it had been a closer family member, of course that would be more upsetting and shocking… [but you] can’t deny the reality that it happened.”
She believes the key to maintaining public support in criminal cases is to keep genetic genealogy for the most serious threats to public safety such as murders. Submitting a DNA test will only tell people the truth, but they should be prepared for the unexpected. “Once you’ve taken a DNA test, you’re opening the door to whatever that might reveal, and people need to brace themselves for what that could unleash,” she says.
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