Police moved Joran van der Sloot to a cell at the prosecutor's office on Thursday as officials prepared to file charges following what they called a remarkably complete confession in the beating and strangling death of a 21-year-old woman.
"We've practically closed the case," criminal police chief Gen. Cesar Guardia told The Associated Press.
Sheathed in a bulletproof vest, the young Dutchman was driven less than a mile across central Lima during rush hour in a police convoy.
Guardia said Van der Sloot, who also remains the lone suspect in the Natalee Holloway missing-teenager case, "confessed with a wealth of details that have been corroborated through criminal investigative rigor."
But he said Peruvian interrogators restricted their questioning to the case of Stephany Flores, the daughter of a circus promoter and former race car driver whom he met playing poker at a casino.
They did not question him about Holloway's disappearance -- exactly five years to the day before Flores was killed.
Guardia denied any suggestion that Van der Sloot's confession was forced. He said a translator assigned by the Dutch Embassy was present, as was a state-appointed defense attorney.
If tried and convicted on murder charges, Van der Sloot would face from 15 to 35 years in prison.
The attorney for the slain girl's family, Edwar Alvarez, told the AP that prosecutors have until 8 a.m. Friday morning to file charges. Otherwise, Van der Sloot would have to be freed.
Still unresolved is the May 30, 2005 disappearance of Holloway on the Caribbean island of Aruba.
Efforts by the FBI to try to solve it may have inadvertently helped fund the travel that enabled the murder of Flores.
Believing it was closing in on Van der Sloot, the FBI videotaped and allowed him to be paid $25,000 in a sting operation in Aruba last month. But it held off on arresting him, and he took the money and flew to Peru.
Guardia told the AP in an interview Wednesday evening that the 6-foot-3 (190-centimeter-tall) Van der Sloot, 22, impressed investigators with both his intelligence and brutality.
"He grabbed her and smashed her with an elbow," Guardia said, pointing to his own nose. "A lot of blood spewed out ... Then he strangles her and throws her to the floor."
"He is irascible. He has no self-control," Guardia said.
The general said Van der Sloot took Flores' cash, about US$300 worth of Peruvian currency, two credit cards and her national ID card. He apparently also took her Jeep Cherokee, which was found abandoned blocks away in a lower-class neighborhood.
Guardia said Van der Sloot attested in his confession to killing Flores because she found out about the Aruba case by using his laptop without his permission. But he said police didn't necessarily believe him and think he may have killed Flores before going out and returning to the room with two cups of coffee and rolls.
"This guy is very intelligent but at times has lapses," said Guardia. "And the truth is that he is not a person in possession of all his senses."
A psychological examination is pending, he said.
Van der Sloot is also getting plenty to eat, Guardia said. "If he wants a steak we give him a steak ... If he wants a cigarette we give him cigarettes."
The evidence against the Dutchman includes hotel security camera video showing Flores and Van der Sloot entering his hotel room together and the Dutchman leaving alone four hours later.
Security camera video from the Atlantic Casino where the two met shows Flores arriving at a poker table where Van der Sloot is sitting with other players, shaking his hand as if they'd met before and then taking the seat next to him. The two later leave together.
"The incriminatory elements were so powerful that he had to confess," said Guardia.
Van der Sloot confessed, police say, on his third full day in police custody and a full week after he fled into northern Chile.
He was charged with extortion in the United States on June 2, the day of his arrest in Chile, in a case the commenced after Van der Sloot contacted John Kelly, a New York lawyer for Holloway's mother Beth Twitty in April, according to an affidavit unsealed on Thursday.
The Dutchman allegedly was seeking $250,000 in exchange for the location of the young woman's body, how she died and the identity of those involved.
Van der Sloot's father died in February and he "wanted to come clean, but he also wanted money," said Bo Dietl, a private investigator who worked with Kelly on the case.
Holloway's family said they wanted closure and Kelly contacted the FBI. It sent 10 to 12 agents to Aruba who set up a sting operation, added Dietl.
In the operation, Kelly gave Van der Sloot $10,000 in cash -- another $15,000 was wired to a bank account in his name -- and told he'd get $225,000 once the body was found, the investigator said.
Van der Sloot was secretly videotaped by the FBI in an Aruba hotel telling Kelly he pushed Holloway down, she hit her head on a rock and died, according to the affidavit. He said he then contacted his father, who helped him bury the body.
Kelly and Van der Sloot then went to where the Dutchman said he and his father -- in the foundation of a house.
No body has been found and the affidavit, signed by special agent William K. Bryan of the FBI's Birmingham, Alabama, office, says Van der Sloot admitted in a May 17 e-mail -- he was in Peru by then -- that he had lied about the location of Holloway's remains.
The investigation of Van der Sloot in the Holloway case was simply not far enough along to have him arrested, the FBI and the U.S. attorney's office in Birmingham said Wednesday.
However, Senate Judiciary Committee Chairman Patrick Leahy quickly asked FBI Director Robert Mueller for an explanation of "exactly what happened in this case and the basis for all actions taken by the FBI."
The affidavit says Twitty wired Van der Sloot $15,000 to his Netherlands bank on May 10.
Van der Sloot was the last person seen with her daughter before the girl vanished on the last night of a high school graduation trip. He was arrested twice but released both times for a lack of evidence.
Flores' family was asked Wednesday for comment on the fact that Van der Sloot traveled to Peru less than a week after receiving the cash in the extortion sting.
Enrique Flores, one of the slain Peruvian woman's brothers, said, "My sister is dead, so I can't accomplish anything by thinking about what might have been."
"Neither I nor the family are thinking about all the things that could have happened but did not."
Associated Press Writers Samantha Gross in New York City, Pete Yost in Washington, Jay Reeves and Kendal Weaver in Alabama and Mike Melia in San Juan contributed to this report.