It’s been almost 50 years since the serial murderer and rapist dubbed the Golden State Killer started terrifying suburban America.

Now, a policeman has formally admitted he committed the disturbing crimes.

Joseph James DeAngelo has told prosecutors he will plead guilty to 13 murders as well as admit to a string of rapes, burglaries and other crimes.

The plea deal enables the 74-year-old to avoid the death penalty.

DeAngelo is suspected of committing at least the 13 murders and more than 50 rapes in the 1970s and 1980s, in one of California’s most vexing cases.

While he will be prosecuted for the murders, he can not be punished for some of the other crimes, including the rapes, because the statute of limitations has passed. But he has agreed to publicly confirm his responsibility.

In a makeshift court set up in a Sacramento university ballroom on Tuesday morning (Australian time), prosecutors began describing each terrifying incident, which often began with DeAngelo waking a couple in their bed.

DeAngelo answered “guilty” and “I admit” in front  of victims and their families, in the hearing which was also being live-streamed.

• Watch the live-stream of the Golden State Killer hearing here

Prosecutors said the serial killer and rapist would break into homes and confront a couple or lone females, at times while children were asleep in the house.

In some cases, he would tie the man up, put dishes on his back and sexually assault the woman in another room.

If the dishes fell he would know the husband was attempting to escape.

The killer would often “taunt” the victims and sometimes loiter in the victims’ home for hours and make himself a snack or drink a beer after the attack.

A woman at an earlier court hearing holds a photo of Cheri Domingo and Gregory Sanchez, who were killed in 1981. Photo: Getty

The disturbing crimes had stretched across the state and initially led to a range of public nicknames in media stories at the time, including the “Diamond Knot Killer”, the “Original Night Stalker” and the “East Area Rapist” and “East Bay Rapist”.

Authorities later realised the crimes were all the work of one man.

He was identified and arrested in 2018 after investigators secretly collected DNA and tracked him down via a genealogy website popular with people exploring their family trees.

Detectives had taken DNA collected from semen found at one of the crime scenes.

They plugged it into several genealogy websites, managing to link it to a distant relative of DeAngelo’s.

Authorities revealed in 2018 former policeman Joseph DeAngelo Jr had been identified as the Golden State Killer. Photo: Getty

Detectives told the Los Angeles Times in 2018 that with that link established, they then focused on DeAngelo because of his “age, employment and that he lived close to where many of the crimes were committed”.