Investigators Capture Golden State Killer through DNA-Sharing Websites

Joseph James DeAngelo was arrested on April 24, 2018 for his suspected crimes as the Golden State Killer. The infamous criminal terrorized California in the ‘70s and ‘80s. After DeAngelo was caught, authorities revealed how DNA shared on a genealogy website helped nab this suspected serial killer and rapist.

How DNA Helped Nab the Accused Golden State Killer

California investigators and the FBI reopened the cold case of the Golden State Killer in 2016. The killer was wanted for a series of murders, rapes, and burglaries in California more three decades ago.

Authorities arrested Joseph James DeAngelo, a former law enforcement officer, on April 24. Investigators revealed how DNA led to the arrest.

Related: Joseph James DeAngelo, Suspected Golden State Killer, Arrested

Thanks to the advancement in DNA technology in the 1980s and 1990s, investigators were able to collect forensic samples of DNA from the killer’s crime scenes. The DNA hinted that there was one man behind the crimes. But there were no matches found in the police’s database.

When the investigation was reopened, investigators created an “undercover profile” and uploaded the Golden State Killer’s genetic profile on the consumer genetics website The website allows users to share their DNA profile and match it with genetic information from larger commercial sites like

There was a match for the DNA. A distant cousin of DeAngelo’s had intended to map his family tree by sharing his own DNA profile. A forensic investigator and expert in DNA profiles, Paul Holes, traced DeAngelo’s ancestry in the family tree all the way to his great-great-great grandparents.

A team of five investigators spent four months painstakingly building a family tree name-by-name. They went through public records until they found one name. The shot in the dark was successful, and DeAngelo, now 72 years old, was arrested in Citrus Heights.

Related: 6 Facts about the Notorious Golden State Killer

Concerns about Privacy

The method by which authorities identified the suspected Golden State Killer is considered groundbreaking. However, the unorthodox method has also raised ethical concerns about the privacy of our genetic information.

GEDmatch is an open-source website, and its policy warns users that their information could be used for other purposes. Personal genomics sites could possibly hand over user information to law enforcement. Many even receive multiple legal notices for such information, although the websites deny sharing user data to police.

But in this case, law enforcement made a fake profile to find a match for DNA evidence. Police claim that no violation of privacy was committed during the investigation.

This new forensic investigative method could also have serious ramifications. Just because a suspect’s DNA matches the DNA evidence recovered at a crime scene, that does not mean the suspect is necessarily guilty.

The Golden State Killer case could have an impact on DNA testing and genealogy-sharing sites. Perhaps people will hesitate to share their DNA profile on consumer genetics sites in the future.