SACRAMENTO, Calif. (NewsNation) — A former California police officer who was unmasked as the “Golden State Killer” was sentenced to life in prison on Friday for a more than decade-long string of murders and rapes across the state.

Sacramento County Superior Court Judge Michael Bowman said 74-year-old Joseph James DeAngelo will die in prison for his guilty pleas to 13 murders and 13 rape-related charges between 1975 and 1986.

DeAngelo pleaded guilty in June to the murder and rape charges under a plea deal that spares him the death penalty. He also publicly admitted to dozens more sexual assaults for which the statute of limitations had expired.

The sentencing follows four days of emotional hearings in which victims or their family members confronted him in court.

Before his sentencing, DeAngelo rose from a wheelchair, took off his mask and said to the court: “I listened to all your statements, each one of them, and I’m truly sorry for everyone I’ve hurt.”

Prosecutors called his spate of crimes “simply staggering,” encompassing 87 victims at 53 separate crime scenes spanning 11 California counties.

The case set several hallmarks.

To finally identify and arrest him in 2018, investigators pioneered a new method of DNA tracing that involves building a family tree from publicly accessible genealogy websites to narrow the list of suspects.

They linked nearly 40-year-old DNA from crime scenes to a distant relative, and eventually to a discarded tissue they surreptitiously sneaked from DeAngelo’s garbage can in suburban Sacramento.

The same technique has since been used to solve 93 murders and rapes across the nation, said Ron Harrington.

“It is probably the most important (recent) advancement by law enforcement in solving cold case murders and rapes,” he said.

His family has been obsessed with solving the 1980 slayings of youngest brother Keith Harrington and his new wife, Patrice Harrington.

It led oldest brother Bruce Harrington to champion Proposition 69, passed by California voters in 2004, that expanded the collection of DNA samples from prisoners and those arrested for felonies and has since led to more than 81,000 identifications.

The brothers were among family members and survivors who gave three days of testimony before DeAngelo was sentenced.

Most said they will never be the same, even as they told of their resilience and the bond they have formed since DeAngelo’s arrest.

The sweep of his crimes is measured by the mysterious stalker’s nicknames over the years, prosecutors said: the Visalia Ransacker, thought to be responsible for about 100 burglaries and one slaying in the San Joaquin Valley farm town; the East Area Rapist; the Original Night Stalker; and finally, the Golden State Killer when investigators linked the crimes that stretched across much of the state.

“He started off as a Peeping Tom, a voyeur, somebody lurking around women’s bedrooms at night peering in. He then became a two-bit burglar, breaking into women’s bedrooms, stealing trinkets and women’s underwear,” Ron Harrington recalled.

That escalated to raping single women, then to humiliating couples.

His technique became his trademark: He would force his victims at gunpoint to bind themselves with shoelaces, then balance plates on the man’s back with a warning that he would kill both victims if he heard the plates rattle while he raped the woman.

He killed three early Northern California victims when they interfered with his assaults on women. But he escalated again when he moved to Southern California, to 10 known murders.

Even DeAngelo’s ex-wife, Sacramento attorney Sharon Huddle, said in a court filing Thursday that she was fooled.

“I trusted the defendant when he told me he had to work, or was going pheasant hunting, or going to visit his parents hundreds of miles away,” Huddle wrote.

Many victims asked Bowman to make sure DeAngelo is sent to a remote prison and housed among other inmates instead of in protective custody, though state corrections officials said they will make the final decision on where and how he is housed.