Joran van der Sloot, the prime suspect in the unsolved disappearance of Alabama teenager Natalee Holloway, has confessed to killing her and disposing of her remains before attempting to extort the girl's grieving family, court documents state.

The initial revelation came via U.S. Judge Anna Manasco Wednesday during a sentencing hearing in U.S. federal court where van der Sloot, 36, agreed to plead guilty to charges accusing him of extortion and wire fraud charges.

Federal prosecutors accused van der Sloot in a 2010 indictment of hatching a plot to sell information about the whereabouts of Holloway’s remains to her grieving family in exchange for $250,000. The Dutch national, who had been serving a 28-year prison sentence in South America for the 2010 murder of a Peruvian business woman, was extradited to the U.S. in June to stand trial in the Northern District of Alabama.

Van der Sloot has not been charged in Holloway's presumed death. The federal charges to which he confessed were the only ones to have ever been linked to the disappearance of Holloway, who was last seen in May 2005 and later declared dead.

As a condition of the plea deal, van der Sloot agreed to reveal how Holloway died and how her body was disposed of, according to a federal sentencing memorandum. He was sentenced Wednesday to 20 years in prison, but as part of his plea agreement, that sentence will run concurrently with his sentence in Peru on the murder case, court records state.

USA TODAY has reached out to attorneys representing van der Sloot and the U.S. for more information.

Manasco said she considered van der Sloot’s confession to Holloway's murder and the destruction of her remains as part of the sentencing decision, the Associated Press reported.

“You have brutally murdered, in separate instances years apart, two young women who refused your sexual advances,” the Associated Press quoted the judge as saying.

Holloway's mother, Beth, told assembled reporters after the hearing that van der Sloot admitted to killing the teenager on a beach before dumping her into the water. Though van der Sloot cannot be tried in the U.S. for the apparent murder even with a confession, Beth said in prepared remarks that the knowledge gave her a sense of peace.

"It's been a long and painful journey, but we finally got the answers we've been searching for for all these years," Beth said. "I'm satisfied knowing that he did it, he did it alone and he disposed of her alone."

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What happened to Natalee Holloway?

Holloway, who is from Birmingham, Alabama, was 18 years old when she vanished during a trip with high school classmates to Aruba.

The teen was set to fly home from the Dutch Caribbean island on May 30, 2005, but never appeared for her flight. It was later learned that her last known sighting was when she was spotted leaving a night club in Oranjestad.

The mystery garnered years of news coverage and became the subject of numerous true-crime docuseries and podcasts.

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Who is Joran van der Sloot?

The son of a judge who grew up on the island, van der Sloot became the prime suspect in Holloway's disappearance after investigators concluded he was among the last people to have seen her alive.

When Holloway left the night club, she was with van der Sloot and two other men, brothers Deepak Kalpoe and Satish Kalpoe, according to the FBI. The group was seen around 1:30 a.m. that day leaving the area in a silver car.

Police in Aruba arrested and released van der Sloot and the Kalpoe brothers multiple times in 2005 and 2007 in connection with Holloway’s disappearance, but none of them were ever charged with harming her.

Van der Sloot is serving a 28-year prison sentence after he confessed to the murder of 21-year-old Stephany Flores in his hotel room in 2010 after meeting her in a casino. Investigators suggested that he became angry and killed Flores when he discovered that the woman had seen information on his computer about the Holloway case.

Van der Sloot also stole her money and credit cards and briefly fled the country.

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Van der Sloot's U.S. extortion case

Van der Sloot became of interest to U.S. prosecutors when evidence surfaced suggesting he was trying to profit off of Holloway's disappearance and presumed death.

Prosecutors in the U.S. accused van der Sloot in an indictment of accepting $25,000 in cash from the Holloway family in 2010 in exchange for a promise to lead them to her body in Aruba. Van der Sloot had demanded that Holloway's mother pay him another $225,000 when the remains were recovered, an FBI agent wrote in a sworn affidavit filed in the case.

Holloway’s mother wired $15,000 to a bank account van der Sloot held in the Netherlands while an undercover agent gave him another $10,000 in person when the pair met in Aruba, court documents state. Once he had the initial $25,000, van der Sloot showed the agent during a recorded undercover operation where Holloway was apparently buried in the gravel under the foundation of a house.

However, court records stated that van der Sloot later admitted in emails that he had lied and that the information he had provided about the location of the remains was "worthless."

Both Peru and the United States agreed earlier this year to extradite van der Sloot to Alabama and temporarily transfer his custody to the U.S. while he awaited the resolution of the federal case.

Contributing: Natalie Neysa Alund, USA TODAY; Associated Press

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]