Van der Sloot is a self-described liar, having confessed to killing Holloway and later retracting the confessions. He is the last person known to have seen her alive on the Caribbean island of Aruba.
He was convicted of robbing and killing of Stephany Flores in a Lima hotel room after meeting her in a nearby casino in 2010.
The Dutchman is wanted by authorities in the U.S. for allegedly extorting money from the Holloway family on the promise of revealing the location of her body.
He could resist extradition to the United States, where is wanted in the Holloway case, if he obtains Peruvian nationality. That would be a possibility if he becomes the father of a Peruvian child or if he marries a Peruvian citizen.
Van der Sloot is appealing his conviction.
Associated Press writer Franklin Briceno reported this story in Lima and Toby Sterling reported from Amsterdam.