According to Peruvian authorities, van der Sloot confessed to killing Flores, a 22-year-old Peruvian woman he had met only hours earlier when playing poker, because she found something on his laptop computer -- something she was never meant to see.
"I did not want to do it," van der Sloot confessed to police, but "the girl intruded into my private life."
Van der Sloot's private life, however, has been fodder for international headlines around the world his entire adult life. Although the subject of numerous police investigations and undercover press probes, what is still not known about van der Sloot is what makes him tick and if there are other women who have met the same grisly fate as Flores.
"He is a narcissist and he has no impulse control," Harold Copus, a former FBI special agent hired by Holloway's family to investigate van der Sloot, told ABCNews.com. "He might not set out to murder. I don't believe he's a serial killer. He's just extremely arrogant and believes he can get away with anything."
The profligate son of an Aruban judge, van der Sloot, at 18, became the subject of international intrigue for his alleged role in the disappearance of Natalee Holloway, a 17-year-old American high school girl who vanished from an Aruban beach on May 30, 2005, exactly five years before Flores was killed.
The snippet of van der Sloot's confession, made three days after authorities arrested him in Chile, shed some light on a young man whose 22-year-old life has been defined by scandal and arrests.
Prior to his arrival in Peru, van der Sloot had been trying to sell information about Holloway, first to journalists and, according to a U.S. federal indictment, to an individual in Alabama who sources say is Holloway's mother, Beth Twitty.
In the five years since Holloway disappeared, the unemployed van der Sloot spent much of the time gambling, partying and soliciting women.
He also has been suspected of murdering two women, arrested three times, indicted on extortion charges, and accused of trafficking women in Thailand for sex.
Just after news broke that van der Sloot was wanted for the Flores murder, Dutch journalist Jaap Amesz interviewed a friend of van der Sloot's who described him as broke, "completely desperate and pretty depressed."
"I was in touch with Joran until right before May 30," the friend told Amesz. "He was in Peru. That was known. In Aruba, he couldn't deal with it anymore. His relationship with his mother was getting worse. He had gambled money away again. This is what preceded his flight to Peru. Right before the weekend, it was clear that Joran was in financial trouble, and he was pretty confused. Driven by hunger, the fear of not being able to pay for his hotel. He desperately needed money. I have never seen Joran so frustrated as in this period."
"He asked me on several occasions to send money, and was [by his own account], completely desperate and pretty depressed. He asked for small amounts [to eat], and became pretty angry when I refused to send anything. He said literally that he was capable of strange things because no one wanted to help him," the friend told Amesz.
That is a far cry from 2005, when van der Sloot was described by the Associated Press as "an honors student at the Aruba International School" who enjoyed a privileged life in the labyrinthine streets of an island paradise.
From the age of 16, he regularly visited the island's casinos, gambling on a $5,000 line of credit in his father's name. On the night Holloway disappeared, he had been gambling with his father, Paulus, who was known to spend more time on the tennis court than in his courtroom.
Van der Sloot could act with impunity in Aruba because he knew the judge, said Copus.
"His father was a judge and his best friend was the police chief. In southern vernacular, Joran was the beneficiary of 'home cooking.' When you know the judge and the police department there's not a lot left to be against you," Copus said.
Although arrested twice in Holloway's disappearance, he was never tried for it.
Van der Sloot, even at a young age, earned a reputation for "preying on girls, allegedly slipping them a date rape drug and taking advantage of them," Copus said.
In the years since Holloway's disappearance, van der Sloot has maintained a lifestyle similar to those of his teenage years in Aruba, playing poker and picking up women.
He left Aruba in 2006, returning to Arnhem, the Netherlands, where he briefly studied engineering.
Holloway's parents tried suing van der Sloot and his parents in 2006, seeking civil damages in a U.S. court. In their complaint, they described the Dutch teen as leading a "violent and anti-social lifestyle."
Van der Sloot was back in the news in 2008 for allegedly preying on women when he was captured in a sting by Dutch crime journalist Piet de Vries.
Using hidden cameras, de Vries recorded van der Sloot trying to convince Thai women to go to Europe to work as sex workers. That same year, de Vries interviewed van der Sloot on a Dutch talk show, which ended when van der Sloot threw a glass of wine in reporter's face.
Van der Sloot's father, Paulus, one of Aruba's four judges, died in February 2010, leading Joran van der Sloot to return to Aruba. But according to the friend, it also led to a breakdown and plans to enter therapy.
Van der Sloot supposedly realized he needed help.
"In the weeks before the murder, things went totally awry with Joran. After the death of his father Joran went to live in Aruba again. Joran had new plans for the future. He was going into therapy ... to give his life shape again," the friend told Amesz.
"A week after he was going to be admitted, this happens," the friend said.