Richard Cottingham — who is already serving time in state prison for several other murders — is charged with two more counts of murder for Tuesday's confession
Richard Cottingham

A notorious New Jersey serial killer pleaded guilty Tuesday to the cold case murders of two teenage girls in 1974.

Richard Cottingham — who is already serving time in state prison for several other murders — admitted to kidnapping and raping 17-year-old Mary Ann Pryor and 16-year-old Lorraine Marie Kelly before murdering them in 1974, according to the Bergen County Prosecutor's Office.

Pryor and Kelly were last seen walking together on Broad Avenue in Ridgefield, New Jersey, on August 9, 1974. Witnesses told police that they had seen the two girls hitchhiking, and they had gotten into a vehicle with an unknown white male.

The teenagers were reported missing after they didn't return home that night. Their bodies were found five days later, the prosecutor's office said.

"This is a somber day as we revisit the horrific acts and terror this man brought upon Bergen County nearly 50 years ago," Bergen County Prosecutor Mark Musella said in a statement.


"It is my fervent hope that this arrest and conviction bring some semblance of closure to the friends and family of Mary Ann and Lorraine and a measure of justice to members of our communities, who have long feared this unknown actor."

Cottingham, 73, is charged with two more counts of murder for Tuesday's confession, which he gave to Chief of Detectives Robert Anzilotti who had been interviewing Cottingham over the past 15 years in an attempt to find out if he was responsible for other killings.

He is expected to be sentenced with two life sentences in July, which will be served concurrently with the time he's already serving as part of a plea agreement, according to The Associated Press.

In court Tuesday, Cottingham admitted that he brought the two girls to a motel room where he raped them and then drowned them in the bathtub, AP reports.

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His defense attorney, John Bruno, reportedly said that Cottingham hoped to bring the girls' families closure.

"He's relieved that this cloud that's been hanging over his head for many, many years is now removed," Bruno said, according to AP.

Bruno did not immediately respond to PEOPLE's request for comment.

Cottingham is already serving a life sentence in state prison. Authorities have linked him to 11 murders so far, including three that he confessed to last year, though they suspect the death toll may be higher.

He has become known as the "Torso Killer" for dismembering his victims by cutting off their limbs and head, leaving only their torsos. He has claimed to be responsible for as many as 100 murders, AP says.