While the lengthly list of charges was read in court, van der Sloot, wearing a greet T-shirt and sweating, hung down his head. Earlier, he told the court he was "truly sorry" for the killing of 21-year-old Stephany Flores and said that he had initially wanted to "confess sincerely" for his crime.
His murder victim, Flores, was killed five years to the day after the American teen Natalee Holloway disappeared in Aruba, a case in which van der Sloot remains the prime suspect.
In court on Wednesday, van der Sloot told the panel of three judges who would decide his fate, "I want to plead guilty. I truly am sorry for this act. I feel very bad."
By admitting his guilt, it was believed the 24-year-old was hoping for a reduced sentence rather than the 30-year sentence being sought by prosecutors. Peru does not have the death penalty or life sentences.
The Dutch playboy's lawyer, José Jimenez, said that his client killed Flores, the daughter of race car driver and businessman Ricardo Flores, because of "extreme psychological trauma" after being "persecuted" over the disappearance and possible murder of Holloway, "something he says he never did and for which no evidence at all exists."
In a separate legal decision due on Thursday, a judge in Alabama declared that Holloway was legally dead. In September, the court ruled that her father, Dave Holloway, had made the legal presumption that she was dead. Since then, said his attorney, no evidence has surfaced to prove otherwise.
Reaction from Natalee's Mother"He's tortured, tormented and taunted [Natalee's mother] Beth Holloway for six-and-a-half years and toyed with her emotions nonstop about what fate fell to her daughter with absolutely no remorse, and now seeks to use that as a basis to mitigate his prison time for brutally murdering another young woman," Beth Holloway's attorney, John Q. Kelly, tells PEOPLE. "It's rather incredible."
In the days before he traveled to Peru, van der Sloot collected $25,000 from Beth Holloway for information about Natalee's whereabouts in one of several shifting accounts. That information proved false, prompting U.S. federal officials to bring extortion and wire fraud charges against him.
Once van der Sloot was sentenced in Peru, the U.S. Attorney's Office in Birmingham, Ala., could begin efforts to bring him to trial in the States, where any punishment could be tacked on to prison time for the Peru murder to be served here or abroad, said Kelly.
"You want to make sure the witnesses and evidence are fresh," the attorney said of the U.S. criminal charge. "That's why you want to proceed immediately."