Authorities in California made an arrest this week of who they believe to be the notorious Golden State Killer, who was allegedly responsible for 12 deaths and upwards of 50 rapes in the 70s and 80s, after decades of searching.

The big picture: The methods that got them to Joseph James DeAngelo, 72, on Wednesday, are raising concern with ethicists and scientists about the availability of DNA to law enforcement.

Who is he?

• The L.A. Times reports that DeAngelo is a Navy veteran, and joined the police department in Exeter, California, in 1973. He is reportedly married with three daughters.
• When law enforcement came to arrest him on Wednesday, DeAngelo was "doing a woodworking project in his garage," and asked agents if he "could take out a roast he had cooking inside."

What did he do?

• Per CNN, he is accused perpetrating "12 deaths and at least 50 rapes...from 1974 through 1986" in 10 California counties.
• Per the L.A. Times, DeAngelo began as a burglar in Visalia. When he moved to Auburn for work, he began slipping into homes and raping women.
• Police believe he began killing after being let go from the Auburn force.
• He is being charged with the 1980 killing of Lyman and Charlene Smith, and the suspected murder of Brian and Katie Maggiore in 1978, the Daily Beast reports.

How they found him

• A separate L.A. Times report says authorities had "a string of DNA" left at several of the murder scenes.
• Investigators used GEDmatch.com, a public genealogy site, to narrow down their search, NPR adds.
• DeAngelo's DNA was "secretly retrieved...from a discarded item" while he was under surveillance, reports the Times, and matched to the samples from the murder scenes.
• The New York Times explains that scientists are concerned about the "[p]rivacy and ethical issues glossed over" by DNA databases.