Natalee Holloway's suspected killer, Joran van der Sloot, admits to crime, says mother

A man long thought to have killed Alabama teenager Natalee Holloway 20 years ago has admitted to the crime, her mother has said.

Joran van der Sloot pleaded guilty on Wednesday to extorting money from the family and as part of a plea deal he had to reveal how the teenager died.

"He is the killer," Beth Holloway told reporters outside the Birmingham court.

Her daughter, then 18, disappeared from Caribbean island Aruba in 2005 after leaving a bar with Mr van der Sloot.

The Dutchman will serve his 20-year sentence in Peru where he was already behind bars for another murder.

In 2010 he demanded $250,000 from her mother in exchange for information.

"You have finally admitted that, in fact, you murdered her," her mother, Beth, said to him in court on Wednesday, according to news site AL.com.

She also said he had "bludgeoned" her daughter, who would have turned 37 this month, the site reported.

His confession was documented in a court filing and outlined by Judge Anna Manasco as she sentenced him.

"You have brutally murdered in separate incidents years apart two beautiful women who refused your sexual advances," she said.

In exchange for the sentence of 20 years, Van der Sloot agreed "to provide full, complete, accurate, and truthful information regarding Natalee Holloway's disappearance", the Justice Department said.

It is not clear how much of that information will be shared with the public.

Despite international attention to the case, the teenager's remains were never found and in 2012 she was declared dead by a court.

She had gone to Aruba with friends to celebrate graduating from high school.

While van der Sloot was the primary suspect in her disappearance for nearly 20 years, he was never charged.

A grand jury in 2010 indicted Van der Sloot on two charges extortion and fraud. He had received money from the family to explain how Natalee Holloway died and show them where she was buried, but only gave them lies.

Van der Sloot was extradited from Peru to the US in June to face the extortion charges.

He admitted in 2012 to the 2010 murder of college student Stephany Flores and will return to Peru to serve his new sentence concurrently.