SACRAMENTO, Calif. >> A DNA match led to the arrest of a 72-year-old former police officer in one of the most baffling and sadistic crime sprees of the 1970s and ’80s — a string of at least 12 slayings and 45 rapes in California by an attacker dubbed the Golden State Killer, police said today.

Armed with a gun, the masked attacker would break into homes while single women or couples were sleeping. He sometimes tied up the man and piled dishes on his back, then raped the woman while threatening to kill them both if the dishes tumbled. He often took souvenirs, notably coins and jewelry, from his victims, who ranged in age from 13 to 41.

The match led to Joseph James DeAngelo, who was fired in 1979 from the police department in Auburn, northeast of Sacramento. Despite an outpouring of thousands of tips over the years, his name had not been on authorities’ radar before last week, District Attorney Anne Marie Schubert said.

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“We knew we were looking for a needle in a haystack, but we also knew that needle was there,” Schubert said. “We found the needle in the haystack, and it was right here in Sacramento.”

“The answer was always going to be in the DNA,” she said.

Sacramento County Sheriff Scott Jones referred to the genetic material as “discarded DNA,” but authorities refused to give specifics about how it was collected or matched to the suspect.

DeAngelo was arrested on suspicion of committing four killings in Sacramento and Ventura counties, authorities said.

“Very possibly he was committing the crimes when he was employed as a peace officer,” Jones said.

The suspect was fired from the Auburn department in 1979 after he was arrested for stealing a can of dog repellant and a hammer from a drug store, according to Auburn Journal articles from the time.

FBI agents were gathering evidence at a Sacramento-area home linked to DeAngelo, the agency said.

As the crimes unfolded across the state, authorities called the attacker by different names. He was dubbed the East Area Rapist after his start in Northern California, the Original Night Stalker after a series of Southern California slayings and the Diamond Knot Killer for using an elaborate binding method on two of his victims.

He was most recently called the Golden State Killer.

Jane Carson-Sandler was sexually assaulted in 1976 in her home in Citrus Heights by a man believed to be the East Area Rapist. She said she received an email today from a retired detective who worked on the case telling her they had identified the rapist and he was in custody.

“I have just been overjoyed, ecstatic. It’s an emotional roller-coaster right now,” Carson-Sandler, who now lives near Hilton Head, South Carolina, told The Associated Press in a telephone interview. “I feel like I’m in the middle of a dream and I’m going to wake up and it’s not going to be true. It’s just so nice to have closure and to know he’s in jail.”

In 2016, the FBI and California officials renewed their search for the East Area Rapist and announced a $50,000 reward for his arrest and conviction. He was linked to a total of more than 175 crimes between 1976 and 1986.

Authorities decided to publicize the case in advance of the 40th anniversary of his first known assault in Sacramento County.

DeAngelo, who was also a police officer in Exeter, in Southern California, from 1973 to 1976, was taken into custody without incident as officers surprised him at his Sacramento-area home, Jones said.

“This was a truly a convergence of emerging technology and dogged determination by detectives,” Jones added.

Neighbors knew DeAngelo as a man who whose angry, curse-filled outbursts would carry through the neighborhood if he couldn’t find his keys or something else set him off.

“He liked the F-word a lot,” neighbor Natalia Bedes-Correnti said.

He never yelled at people, she said, just lashed out when he’d get frustrated.

“He’d be out on his driveway yelling and screaming, looking for his keys,” she said. “I could hear him from inside my house yelling and screaming. He was very loud.”

But he hadn’t had an outburst in several years, she said, and she assumed he was mellowing in old age or receiving professional help.

Kevin Tapia, now 36, said when he was a teenager, DeAngelo falsely accused him of throwing things over their shared fence, prompting a heated exchange between DeAngelo and Tapia’s father. He said DeAngelo could often be heard cursing in frustration in his backyard.

“No one thinks they live next door to a serial killer,” Tapia said. “But at the same time I’m just like, he was a weird guy. He kept to himself. When you start to think about it you’re like, I could see him doing something like that, but I would never suspect it.”