• The Listener
  • North & South
  • Noted
  • RNZ
The alleged “Golden State Killer”, Joseph DeAngelo Jr, makes a court appearance in California last year. The 72-year-old former police officer became the prime suspect after investigators used a genealogy website’s data to match DNA evidence from the crime scenes with one of his distant relatives. Photo/Getty

Framed by DNA: Should police have access to genealogy databases?

Should police have access to genealogy databases – and do the innocent have anything to fear?

No wonder detectives thought they had their man in a 2012 murder case in the United States that could have put 26-year-old Lukis Anderson on death row; his DNA was found on the victim’s fingernails. Even Anderson, a homeless alcoholic, thought he might have done it. Only some digging by a conscientious public defender showed he was actually in hospital across town, detoxing, when the killing took place.

It took months to work out what had happened. The two ambulance officers who picked a near-comatose Anderson off the street were the same paramedics later called to the murder scene, and had inadvertently transferred traces of Anderson’s DNA to the body.

Auckland private investigator Tim McKinnel, who helped overturn Teina Pora’s wrongful conviction for murder, says DNA has been a game changer for both the prosecution and the defence. But he warns we should tread with caution: people continually shed DNA wherever they go, and evidence based on “touch” (or low copy number) DNA comes with substantial risks. “We need to be careful we don’t create an environment where each of us must maintain a diary or record of where we have been and why, in case we are one day required to account for the presence of our DNA at a crime scene.”

Last year, a man dubbed the Golden State Killer was charged with a string of cold-case murders in California after investigators used the open-source genealogy website GEDMatch to compare DNA evidence with profiles stored on the database – scoring a hit when it matched a distant relative, leading them to the man now facing trial. So far, police here have ruled out accessing genealogical databases to identify possible suspects, but it’s one of a number of issues up for discussion in a Law Commission review. A final report is due to be released before the end of the year.

Related articles: How the use of DNA in criminal investigations could violate your human rights | Why it took so long to catch Teresa Cormack's killer | How police used DNA to solve some of NZ's high-profile criminal cases


New Zealand was the second country in the world to create a legislative regime for the use of DNA in criminal investigations, but Law Commissioner Donna Buckingham says developments since it was introduced in 1995 “raise questions on which informed public debate is needed”. Currently, there are two DNA databases in New Zealand: one stores samples of unknown DNA found at crime scenes; the other holds genetic information of some 185,000 people charged with or convicted of certain crimes, or who have voluntarily supplied a sample.

Familial searches of these databases, looking for matches with unidentified DNA, are tightly restricted – although that, too, has been flagged by the Law Commission as an area for review. In California, where there are no such constraints, the strategy has led to at least another 10 high-profile arrests, including the so-called “Grim Sleeper” in Los Angeles and the “Roaming Rapist” in Sacramento. This March, DNA from the tears frozen on the face of a dead baby found abandoned in South Dakota 38 years ago was uploaded to a genealogy website; a match with relatives led to the boy’s mother being charged with murder.

The approach hasn’t been without controversy, however. Privacy concerns led to GEDMatch changing its policy in May, so people can choose whether to share their genetic information with criminal investigators rather than giving consent by default, while DNA-testing company FamilyTreeDNA now allows customers to opt out, after weathering a public backlash for working with the FBI.

Ancestry.com (the parent company of AncestryDNA) and 23andMe both say they do not engage with criminal investigations. “It’s our policy to resist any law-enforcement inquiries with all legal and practical means at our disposal,” 23andMe’s Andy Kill told the US media last year.

Waikato University’s Andelka Phillips echoes Tim McKinnel’s concerns about how personal data might be used in criminal investigations. Prosecutors in the Golden State Killer case, she notes, are calling for the death penalty. “People think, ‘It’s never going to be me,’ but the mere presence of DNA somewhere isn’t synonymous with guilt. Most of us can leave DNA traces virtually wherever we go without knowing it. It could have quite unpleasant consequences for people, and they may be innocent.”

Written in the genes

Whether it’s resolving a mystery or revealing a secret, DNA has become a powerful tool. Here are just a handful of cases that have made headlines in the past few years.

  • August 2019 An Ohio couple file a lawsuit against a fertility clinic that swapped the husband’s sperm for a stranger’s. The man discovered he is not their daughter’s biological parent after the 24-year-old gave him an ancestry kit for Christmas.
  • August 2019 A woman conceived when her mother was raped as a 13-year-old by a family friend tells the BBC she wants her birth father prosecuted using her own DNA. “I’ve got DNA evidence because I am DNA evidence,” she says. “I’m a walking crime scene.”
  • June 2019 A Canadian fertility specialist loses his medical licence for using the wrong sperm, including his own, to inseminate as many as 50 IVF patients.
  • May 2019 A 31-year-old labourer is confirmed via a DNA test as the biological heir of an English aristocrat who committed suicide in 2018, leaving behind an estate valued at £50 million.
  • February 2019 A woman in Phoenix, Arizona trying to trace her biological father takes a DNA test and finds she has a half sister, born just months apart, living in the same city; both were conceived by donor sperm from a New Zealand doctor who lived there in the early 1980s.
  • November 2018 UK millionaire Richard Mason claws back £4 million from a divorce settlement paid out to his ex-wife after a DNA test confirmed he was not the father of their three sons. Mason has been diagnosed with cystic fibrosis, a condition that leaves most men infertile.
  • April 2018 The DNA Doe Project announces it has solved its first cold case, identifying a murder victim known only as the “Buckskin Girl” after her body was found in a ditch in Ohio in 1981. Founded in 2017 by two American forensic genealogists, the project sequences DNA from unidentified bodies, then uses public database GEDMatch to look for relatives with an overlapping genetic profile.
  • September 2017 A High Court judge rules that former cabinet minister and Auckland mayor John Banks is the father of Japan-based English teacher Anthony Shaw. Banks had refused to undergo a DNA test, a fact Justice Patricia Courtney took into account when making a legal declaration “on the balance of probabilities” that Shaw was his biological son. Shaw had grown up believing his father was a Chinese man, Harry Wong, who paid child support for 15 years but wasn’t involved in raising him.
  • April 2016 Archbishop of Canterbury Justin Welby discovers through genetic testing that his real father was Winston Churchill’s private secretary, Sir Anthony Montague Browne. In a statement, Welby’s mother says she’d slept with Sir Anthony before her marriage, “fuelled by a large amount of alcohol on both sides”, but didn’t realise he was the father.                           

This article was first published in the October 2019 issue of North & South as part of the feature How genetic tests are tearing families apart – and bringing others together. Follow North & South on Twitter, Facebook, Instagram and sign up to the fortnightly email for more in-depth journalism.