The decadeslong search for the Golden State Killer — who police say committed 12 murders, 45 rapes and 120 home burglaries during a 12-year reign of terror in the 1970s and '80s — may be finally over.

Joseph James DeAngelo, a 72-year-old former police officer, was arrested overnight by police in Sacramento on a warrant out of Ventura County, California, for two murder charges, officials said Wednesday.

DeAngelo was being held without bail in the Sacramento County Main Jail, according to records.

"We found the needle in the haystack and it was here in Sacramento, " Sacramento District Attorney Anne Marie Schubert said in a news conference with Sheriff Scott Jones and other law enforcement officials.

Jones said they got some discarded DNA to confirm that DeAngelo was their man and arrested him at his modest home in Citrus Heights, California.

After the newlyweds were killed, Harrington bankrolled an initiative passed by California voters in 2004 that mandates collection of DNA samples from people arrested in felony cases.

Also called the East Area Rapist and the Original Night Stalker, the mysterious maniac was blamed for a battery of crimes up and down California starting in 1974 and ending — for reasons still unexplained — in 1986.

From Sacramento south to the Los Angeles suburbs, he raped women who were home alone, women who were with their children, and killed women and men together, police said.

The search for the suspect took on a renewed urgency earlier this year after a book about the case written by the late Michelle McNamara called "I'll Be Gone in the Dark" was published in February with the help of her husband, comic-actor Patton Oswalt.

Contra Costa County cold case investigator Paul Holes, who had worked on this case for decades, told NBC's Megyn Kelly last month the serial killer would follow the news accounts of his crimes and kept a step ahead of the pursuing police by changing the way he targeted his victims.

“He covered his trail very well,” Holes said. “What he didn’t account for was DNA technology.”