Good morning.

(Want to get California Today by email? Here’s the sign-up.)

For three decades, nothing. And then, in the span of six days, a team of law enforcement officers in Sacramento located and arrested the man they say is behind one of America’s most brutal and mysterious crime sprees, the Golden State Killer.

Joseph James DeAngelo, 72, was living in Citrus Heights, a suburb of Sacramento and a short drive on the freeway from the neighborhoods that he is alleged to have terrorized in the 1970s and 1980s. He is a former police officer who the authorities now say raped more than 50 women and killed 12 people. He wore the badge at the time of many of the rapes.

Prosecutors and police officers on Wednesday said DNA analysis was crucial in linking Mr. DeAngelo with murders in Southern California. They managed to obtain his DNA and make the match. But how did they locate Mr. DeAngelo in the first place? And how are they so confident that Mr. DeAngelo was behind the rash of rapes in the Sacramento area, crimes for which there was no DNA evidence? Details will be forthcoming, officials promised at a news conference on Wednesday.

Read our article here.

For more:

• The Sacramento Bee has listed the killer’s crimes, talked to Mr. DeAngelo’s neighbors, and profiled the distribution center where he worked for decades.