Investigators hunting for the so-called Golden State Killer subpoenaed a genetic website in 2017 while investigating an Oregon man who was misidentified as a potential suspect.
The revelation that investigators compelled a genetic company to provide user information adds to a growing debate about legal and privacy concerns involving law enforcement and companies whose millions of users submit their DNA to discover their heritage.
Court records obtained by The Associated Press last week showed investigators persuaded a judge in Clackamas County, Oregon, a year ago to order a 73-year-old man in a nursing home to provide a DNA sample.
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Investigators compared crime-scene DNA linked to the serial killer to information on a free online genealogical site, YSearch.org. They said they spotted a rare genetic marker that the Oregon man shared with the killer who is believed to be responsible for 12 killings and nearly 50 rapes in the 1970s and 80s.
The website's parent company, which also owns FamilyTreeDNA.com, said Tuesday it received a subpoena the same month that "sought limited information, with respect to a single user account" from federal investigators in California.
The company, Gene-by-Gene Ltd., said it complied with the subpoena "to the minimum degree legally required" but didn't notify the user because it didn't want to interfere with the investigation.
Court documents said there was only one match among more than 189,000 searchable genetic records on the website. The documents identified a specific user ID, the user's first name and the most distant paternal relative in the family tree.
A company spokeswoman told the AP last week it hadn't been contacted by law enforcement, but later disclosed the subpoena after a further review of company records.
The Oregon City man is in extremely poor health in a rehabilitation facility and was unable to answer questions Friday. His daughter said his family wasn't initially aware authorities took his DNA but later worked with the FBI before investigators ultimately determined none of her relatives were viable suspects
Detectives turned to a different genealogical site and arrested a man last week who they say was one of California's most elusive serial killers.
Joseph James DeAngelo, a 72-year-old former police officer, was charged with eight counts of murder, and additional charges are expected. He didn't enter a plea when he appeared in court Friday.
On Tuesday, the AP and several other news organizations filed a motion to unseal DeAngelo's arrest warrant and the search warrants detectives obtained, citing the public's longstanding right to access court records and immense public interest in the case.
Attorneys for the news organizations argue that the warrants may provide additional details about the DNA techniques that were used and "the importance of public access to the warrant information sought here cannot be overstated."
The issue of law enforcement comparing DNA to samples in genealogical databases garnered national attention several years ago when a New Orleans filmmaker was wrongly identified as a potential suspect in an Idaho killing based on a DNA sample that his father had given years earlier as part of a church genealogy project.