Home NEWS Tech Investigators Used DNA Submitted To Genealogical Websites In Their Search For Killer

Investigators Used DNA Submitted To Genealogical Websites In Their Search For Killer


Investigators in Sacramento have confirmed their use of commercial websites specializing in tracing ancestral ties to narrow the focus of their investigation into the Golden State Killer case.

Officials told the Sacramento Bee they were able to winnow down their list of potential suspects to former police officer Joseph James DeAngelo after sample DNA collected at one of the killer’s crime scenes was sent to a commercial site for comparison – returning a hit for a member of DeAngelo’s family and prompting a closer look at the disgraced former officer.

Moving the Citrus Heights man to the top of their suspect list, law enforcement placed his home under surveillance, an officer moving in to collect an item carrying DeAngelo’s DNA after it was discarded by their suspect. DNA from that item matched the killers’, police said, and prompted DeAngelo’s swift arrest by police out of concern for public safety.

It was not immediately known what family member submitted the DNA for testing but investigators have told local media that they utilized an “open-source” DNA sharing website called GEDmatch.com.

The approach, credited by many as the leverage they needed to find “the needle in the haystack,” in the Golden State Killer case, appears to have brought one of California’s most prolonged and sadistic unsolved crime sprees to an end. It also leaves some legal and privacy advocates worried. The process has raised concerns for the privacy of family members who may be unknowingly associated with a suspect, and who may find themselves under investigation as a result.

The painstaking investigative process finally came to fruition last Thursday, officials told The Bee, when the DNA return helped focus attention on DeAngelo as a suspect – a conclusion supported by examination of his whereabouts at the time of the attacks as well as his age.

Sacramento County Sheriff Scott Jones’ investigators set up surveillance on DeAngelo in Citrus Heights, obtaining another DNA sample from something he discarded and then a second “more robust” sample.

Those results came back Monday evening, Jones said, prompting DeAngelo’s arrest – and apparent end to a 44-year murder mystery.

Familial testing as a technique has been in use since California became the first state to authorize it in 2008. Most matches have relied on comparisons made against established criminal DNA databases instead of private genealogical sites.

The Bee reported that a familial DNA match led to the arrest of Sacramento’s “Roaming Rapist,” Derek Sanders, who attacked women and two teenage girls between 1998 to 2003.

Investigators were able to arrest Sanders after securing a partial DNA match to his brother – a convicted rapist with DNA in the system. Deputies followed Sanders to a fast food restaurant and collected his garbage to obtain a DNA sample from a straw he had used – matching that sample to DNA obtained at a crime scene.


  1. Interesting approach that raises some questions. Were the sites working with law enforcement knowingly or were the samples sent in without any official tie to police?

  2. This is really interesting and also kind of scary. I’m thinking a smart lawyer might question the way this identification was made.

  3. I read on another news site that the two most popular ancestral sites, when asked, said they were not contacted or involved.
    Go figure, his brother is a rapist. Wonder how much more will be uncovered.

  4. I think it’s great that a family member interested in tracing their family roots helped solved a cold case. Who am I related to? The Golden State Killer. My guess it was Ancestry.com. Of course they’ll deny being involved. They don’t want to lose business.

  5. I don’t understand all this DNA technology stuff and personally wouldn’t send mine in to some random company, but I’m glad the technology exists and that people do because now a violent, evil man will be forced to acknowledge and pay for his crimes.

    • @Tom – Well said. Yes. The method used here is not without its implications. We’re certain they’ll come up again.

  6. I hope they catch many more this way. Privacy Smivacy! If you want to protect the criminals in your family then don’t get tested.

  7. While I am glad that people may finally be getting the answers they have sought for so long I have to admit the total reliance on a scientific method to identify a suspect is just a little creepy and troubling. I would hope that now the investigators are able to support their identification with physical evidence linking this man to the crimes, which I would not think would be hard given what we know about the killer’s movements and this man’s employment and whereabouts.

  8. I’m just glad they caught him. It sounds like he went dormant at around the time his children were born. It would be interesting to know what they think.

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