Van der Sloot, 22 – who is charged with killing Stephany Flores Ramirez, 21, exactly five years after Natalee disappeared during a graduation trip to Aruba – is reportedly ready to discuss what happened the night Natalee went missing and the location of her remains.
But Matt Holloway, who had just finished the 10th grade when his older sister went missing, tells PEOPLE in his first interview that he doesn't believe van der Sloot. "He's just trying to get a lighter sentence," says Matt. "Right now he just knows he's pretty much screwed on murder."
Matt thinks that van der Sloot, who was arrested twice in the Holloway case but never charged, spoke honestly about the incident only once – in an undercover video aired in early 2008 orchestrated by a Dutch TV journalist. In that unguarded moment, van der Sloot said that Natalee had suffered a seizure on the beach, and that he panicked and called a friend who dumped her body at sea.
"I feel like that was the truth," Matt says. "It's hard to talk about it, but I think he put her in the ocean. That would make the most sense to me. All that stuff where he says she's buried in a swamp or under a house being built, that's not true."
Past LiesDuring an extortion sting in May, van der Sloot told Beth Holloway’s attorney, John Q. Kelly, that Natalee's remains were buried at a former construction site, but it turned out that the house wasn't even being built at the time of Natelee's disappearance.
Van der Sloot's information about the body was traded for $25,000 in cash and wire transfer from Beth Holloway's bank account in an extortion case overseen by the FBI and Aruban authorities. Van der Sloot later left Aruba, presumably with the money, and went to South America where he encountered Flores. The Dutchman was charged with extortion on June 3 – the same day he was arrested in Chile for Flores's murder.
"I wish [the authorities] were able to act sooner," says Matt, "but I understand that they had to build the [extortion] case up so he couldn’t get away for the tenth time, so to say. It's terrible Stephany had to meet Joran like that."
"The main thing is [that] I'm glad that he's finally going to be seeing bars for the rest of his life," Natalee’s brother says. "We’ve already come to terms that she is gone, that I'll never see her again. I just hope nobody ever has to deal with that again, and go through that whole tragedy of missing a loved one."