Disturbing Details: Natalee Holloway's Killer Joran van der Sloot Reveals How and Why He Murdered Her

Joran van der Sloot has finally revealed exactly how — and why — he murdered Natalee Holloway in 2005.

The audio of his roughly four-minute confession was released by federal prosecutors as part of a plea deal in his case related to the high school graduate's death.

In the recording, the 36-year-old said he and Holloway, who was 18 at the time and vacationing in Aruba, began kissing on a beach, but he became angry when she rejected his sexual advances.

"She tells me she doesn’t want me to — to feel her up. Uh, I insist," he recalled. "I keep feeling her up either way. And she, uh, knees me, she ends up kneeing me in the crotch."

After trying to defend herself and ward him off, he got up and kicked her "extremely hard in the face."

"Yeah, she’s laying down unconscious, possibly even, even dead. And I see right next to her there’s a huge cinder block laying on the beach," he admitted of how he ended her life. "I smash her head in with it completely. Yeah, her face basically, you know, collapses in. Even though it’s dark I can see her face is collapsed."

Van der Sloot then picked up an unconscious Holloway and released her into the ocean before he returned home.

He confessed he watched an adult video when he got back, and the following day, he continued on as usual and went to school.

On Wednesday, October 18, van der Sloot plead guilty to wire fraud and extortion, as several years ago, he tried to get the Holloway family to pay him $250K in exchange for information about their daughter.

All of his words to them at the time lead to dead ends. The killer wasn't able to be charged with murder since the statute of limitations in Aruba is 12 years.

At the recent court hearing, Natalee's mother, Beth Holloway, condemned him.

"You didn't get what you wanted from Natalee, your sexual satisfaction, so you brutally killed her," she stated, noting his actions "terminated her dreams, her potential, her possibilities."

"For 19 years you denied killing Natalee Holloway. Your lies have caused indiscernible pain. You have finally admitted that you murdered her," Beth concluded. "You are a killer and I want you to remember that."

The judge sentenced him to 20 years behind bars, but before he begins that stint, he has to finish up his 28 years in prison in Peru, where he killed a woman named Stephany Flores in 2010.

Page Six obtained the audio recording of van der Sloot's confession.