Former police officer Joseph James DeAngelo, 72, was arrested at his home after DNA linked him to crimes attributed to the so-called Golden State Killer and he initially was charged with eight counts of murder and could face dozens more charges, authorities said.
RELATED: What we know about suspected "Golden State Killer" Joseph James DeAngelo
The "Golden State Killer," also known as the East Area Rapist, has been linked to upwards of 50 rapes and 12 murders spanning 10 counties up and down the state of California, Sacramento County District Attorney Anne Marie Schubert said during a Wednesday press conference.
Armed with a gun, the masked attacker would break into homes while single women or couples were sleeping. When encountering a couple, he was known to tie up the man and pile dishes on his back. He threatened to kill both victims if he heard plates crash to the floor while he raped the woman. He then ransacked the house, taking souvenirs, notably coins and jewelry before fleeing on foot or bicycle.
RELATED: Timeline of crimes committed by the Golden State Killer
More counties are expected to file charges soon.
"We knew we were looking for a needle in a haystack, but we also knew that needle was there," Schubert said.
The "Golden State Killer" is also believed to be linked to cases in Orange County. O.C. District Attorney Tony Rackauckas also spoke at the press conference, saying DeAngelo's arrest puts to rest the "haunting question of who committed these terrible crimes."
Joseph James DeAngelo - suspect in the East Area rapes and the Golden State murders. pic.twitter.com/vw5la1A8Kf— Eric Thomas (@ericthomaskgo) April 25, 2018
DeAngelo was fired from the Auburn Police 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. He was also a police officer in Exeter, California, from 1973 to 1976.
The FBI said it has a team gathering evidence at a Sacramento-area home linked to DeAngelo.
Schubert said that DNA helped solve the case in the last six days.
"The answer was always going to be in the DNA," she said, adding that the connection with DeAngelo came in the Sacramento slayings of Brian and Katie Maggiore.
"It is fitting that today is National DNA Day. We found the needle in the haystack, and it was right here in Sacramento," Schubert 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 also suspected in cases attributed to the "Visalia Ransacker."
He was most recently called the Golden State Killer.
VIDEO: FBI offering $50,000 reward to identify 'Golden State Killer'
The notorious killer first struck in Rancho Cordova.
"He came in and had a ski mask on and jumped on the bed and had a knife," according to a victim account from the FBI.
He was also a burglar.
"After it was all over and done with, he went through the stuff in the room, took money out of my purse," a victim said.
In the months that followed, a slew of sexual assaults in the east area of Sacramento County and later Contra Costa County took place. The motive was distinctive and brutal.
"Sock stuffed in my mouth, blindfolded, gagged, hands tied, legs tied, and then, you know, pulled me up like this, because I was on my stomach, and put me back in bed and said, 'If you move, I'm going to kill you,'" a victim said.
That was in the late 1970s. But in 2000, DNA evidence confirmed a link between the Bay Area crimes and murders in Southern California during the 1980s. The "East Area Rapist" had become the "Golden State Killer."
O'Malley says she worked with some of DeAngelo's rape victims as a young volunteer at a rape crisis center in 1977. pic.twitter.com/JBvKF45eee— Eric Thomas (@ericthomaskgo) April 25, 2018
The first locally known victims were 24-year-old Keith Harrington and his wife 27-year-old Patrice Harrington, who were killed in their Laguna Niguel home in 1980.
Keith Harrington's brother spoke at Wednesday's news conference, telling reporters that it's time for victims' families to grieve and "bring closure to the anguish that we all suffered for the last 40 odd years."
In 2016, the FBI joined California officials in their renewed hunt for the suspect, and $50,000 reward was announced for his arrest and conviction. He's linked to more than 175 crimes in all between 1974 and 1986.
The long-sought suspect even called some of his victims after the attacks. Some of those calls were recorded by police.
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.
DeAngelo, who served in the Navy, was a police officer in Exeter, in the San Joaquin Valley, from 1973 to 1976, at a time a burglar known as the Visalia Ransacker was active, Jones said.
He transferred to the force in Auburn in the Sierra foothills near where he grew up outside Sacramento. About 50 crimes, including two killings, were attributed to the East Area Rapist during the three years DeAngelo worked in Auburn, but Jones said it wasn't clear if any were committed while on duty.
DeAngelo was fired from the Auburn department in 1979 after being arrested for stealing a can of dog repellant and a hammer from a drug store, according to Auburn Journal articles from the time. He was convicted of the theft and fined $100.
Ten slayings occurred after he was fired and all took place in Southern California.
Although it's unusual for serial killers to stop, Jones said they have no reason to think DeAngelo continued to commit crimes after 1986, when the last rape and killing occurred in Orange County.
Neighbors knew DeAngelo as a man whose 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."
Actor Patton Oswalt, whose late wife wrote the book "I'll Be Gone in the Dark: One Woman's Obsessive Search for the Golden State Killer," tweeted that he hopes to visit the killer.
KABC-TV and the Associated Press contributed to this report.