SACRAMENTO, Calif. — He was initially dubbed the East Area Rapist after beginning his crimes in Northern California. He later became known as the Original Night Stalker after a series of slayings in Southern California.

Now called the Golden State Killer, he has been linked through DNA and other evidence to at least 12 homicides, 45 rapes and dozens of burglaries across California in the 1970s and 1980s.

"This serial offender was probably one of the most prolific, certainly in California and possibly within the United States," Sacramento County Sheriff's Department Homicide Sgt. Paul Belli said at a news conference where authorities announced a $50,000 reward Wednesday for information leading to the arrest of the elusive serial killer.

Authorities decided to publicize the case in advance of June 18 — the 40th anniversary of his first known assault in Sacramento County.

Belli said investigators are looking for clues concerning other crimes in California and elsewhere that he may have committed.

An FBI website at https://www.fbi.gov/sacramento features maps, sketches and interviews involving the case, and the killer has been made a top priority on the agency's major crimes tip line, 800-CALL-FBI.

The case is also being featured on social media, digital billboards and radio public service announcements.

The effort marks the latest of numerous attempts to identify the man who started terrorizing suburban bedroom communities in 1976 and 1977 east of Sacramento and as far south as Stockton and Modesto.

The masked rapist, armed with a gun, would break into homes while single women or couples were sleeping. He would tie up the man and pile dishes on his back then rape the woman while threatening to kill them both if the dishes tumbled.

Prosecutor Anne Marie Schubert recalled growing up at a time when children rode their bikes unsupervised through the neighborhoods and families rarely locked their doors at night.

"It was a time of innocence. And then in June of 1976, that all changed," she said. "A community was taken hostage."

His victims ranged in age from 13 to 41. He often took souvenirs, notably coins and jewelry.

The area of the rapes was near military bases, so investigators said someone with clues might have moved elsewhere long ago. They believe the killer may have had an interest in the military or law enforcement, in part because he was proficient with firearms.

Investigators believe the rapes and dozens of burglaries often used to scout neighborhoods escalated in 1978, when the killer fatally shot U.S. Air Force Sgt. Brian Maggiore and his wife Katie as they walked their dog.

They believe he moved on to commit several rapes in the San Francisco Bay Area before heading to Southern California.

It wasn't until 2001 that new DNA testing linked him to at least six Southern California homicides between 1979 and 1986. In each case, the killer broke into a house at night and raped the female victim first.

Investigators believe he also committed another four homicides in the region because of similarities in evidence or his methods.

The Southern California killer had been called the Original Night Stalker, to distinguish him from Night Stalker Richard Ramirez, who died of cancer in 2013 before he could be executed for committing 13 mutilation murders in 1984 and 1985.

The killer now being sought was also briefly known as the Diamond Knot Killer for an elaborate knot he used to tie up a Ventura couple before they were beaten to death with a fireplace log in 1980.

The killer was described at the time as white, about 5 feet 9 inches with blonde or light brown hair.

If he's still alive, he would likely be 60 to 75 years old.