Virginia Hughes:

New laws in Maryland and Montana are the first in the nation to restrict law enforcement’s use of genetic genealogy, the DNA matching technique that in 2018 identified the Golden State Killer, in an effort to ensure the genetic privacy of the accused and their relatives.

Beginning on Oct. 1, investigators working on Maryland cases will need a judge’s signoff before using the method, in which a “profile” of thousands of DNA markers from a crime scene is uploaded to genealogy websites to find relatives of the culprit. The new law, sponsored by Democratic lawmakers, also dictates that the technique be used only for serious crimes, such as murder and sexual assault. And it states that investigators may only use websites with strict policies around user consent.

Montana’s new law, sponsored by a Republican, is narrower, requiring that government investigators obtain a search warrant before using a consumer DNA database, unless the consumer has waived the right to privacy.

The laws “demonstrate that people across the political spectrum find law enforcement use of consumer genetic data chilling, concerning and privacy-invasive,” said Natalie Ram, a law professor at the University of Maryland who championed the Maryland law. “I hope to see more states embrace robust regulation of this law enforcement technique in the future.”