Murderers can be tracked down using ancestry websites under a new technique developed by Stanford University scientists.
Detectives in California have already used a public ancestry database to arrest Joseph James DeAngelo, the alleged Golden State Killer, who is believed to have committed at least 13 murders and more than 50 rapes.
However, Stanford’s new computational tool could speed up investigations and make them much easier.
It works by providing new ways for police forensics databases – which can often be patchy – to be used alongside the wealth of data contained in public gene databases, such as Ancestry.com and 23andMe.
These are used by consumers who send in their own DNA samples for analysis to discover more about their family history.
The data on these sites is so large that experts believe it’s possible to use them to identify six in every 10 people in the US who are of European descent, even if they have never provided a DNA sample.
Creating the new tool was a technical feat because the two databases use completely different systems of genetic markers.
Only 2 percent of the population needs to have done a DNA test for virtually everyone’s genetic information to be represented in the data.
While it could help solve crimes, it raises wide-ranging privacy questions: if someone uses a consumer website to trace his ancestry, should that information also be used to identify members of his own family in a criminal case?
Javier Ruiz Diaz, a policy director from the Open Rights Group, said: “The current use of genetic databases by US police is deeply unethical, and possibly unlawful in Europe. The consequences for research could be very negative if people, understandably, refuse to provide samples because of concerns about police access.”
Dave Curtis, who is an honorary professor at UCL’s Genetics Institute and the Centre of Psychiatry at Queen Mary University of London, said: “This could be easily done in the UK, it’s very doable, all it takes is for people to make a genetic profile on these databases and agree to be contacted by people who match with them.
“This means the police could easily make their own profile, upload the DNA from the crime scene, and then match up with the private database, which will allow them to see all the suspect’s cousins…They may be breaking the company’s rules but they won’t be breaking the country’s rules.”