Is There A Serial Killer Lurking In Your Family Tree? You Could Be About To Find Out


Madison Dapcevich


Madison Dapcevich

Freelance Writer and Fact-Checker

Madison is a freelance science reporter and full-time fact-checker based in the wild Rocky Mountains of western Montana.

Freelance Writer and Fact-Checker


Detectives are combing through DNA information stored online by various genetic-testing services in order to catch criminals and put the guilty behind bars. The legalities behind this practice are still in limbo, and it’s sparking what could be one of the biggest debates on digital privacy to date.

Millions of people turn to online services like 23andMe and Ancestry in order to trace their genetic history. With a simple swab of a cheek, a person’s genetic material can fill in blank spaces on their family tree or find early warning signs for disease. Still up for discussion, however, is where that data is stored, who can access it, and all the ways it can be used.


Here’s where the gray area comes into play: third-party service providers allow investigators to access any genetic information that voluntarily submitted acting as a digital storage unit filled to its brim. DNA collected from crime scenes can be compared against online DNA and, if it matches someone in the database, authorities will then reconstruct family trees to find a suspect. 

One DNA-forensics company announced it already used 100 genetic profiles generated from crime-scene DNA to search public databases like GEDmatch. So far, 20 probable cases have been identified.

It comes on the heels of April arrest of the Golden State Killer who eluded investigators for decades before finally being captured with this very method. That same month, DNA probes of a family tree led to the arrest of another man accused of an unsolved double murder dating back more than 30 years ago.

There is little legal precedent when it comes to this sort of evidence. In the United States, genetic material is treated like a fingerprint, releasing it from privacy protections guaranteed under the Fourth Amendment

In recent years, the use of genetic genealogy has been misused and even used to track down non-murderers, as was the case when officials used DNA analysis to track down the biological mother of a fetus following an abortion. In 2016, Apple Inc. went head-to-head with the Federal Bureau of Investigation to determine whether the company was required to unlock an iPhone recovered from the scene of a mass shooting.   


At the core of this debate is how private is users’ information and what does that mean going forward? In the case of genetic genealogy, innocent people who are not suspected of a crime become intrinsically involved in an investigation just because they share some genes with a suspect.

But is sifting through a family tree without a person’s consent the same as searching without a warrant or probable cause? That remains to be determined.

[H/T Bloomberg


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