Thirty-three years after the disappearance of Etan Patz, the only suspect ever arrested is as much an enigma as the missing child case that has baffled investigators for decades.
Unlike psychopaths, who show no remorse, Pedro Hernandez, a 51-year-old New Jersey builder, reportedly broke down emotionally during his confession. And unlike many molesters, Hernandez appeared to have no criminal record.
In addition, police offered no possible motive for the crime, saying only that Hernandez, then a teenaged stock clerk at a Manhattan bodega, confessed to luring the 6-year-old into the bodega for a soda and choking him to death in the basement.
Hernandez has told police he then stuffed Etan's body into a plastic bag that was thrown into trash elsewhere in the neighborhood. The body was never found.
He admitted to family members and friends as early as 1981 that he had "done a bad thing and killed a child in New York," according to NYPD Commissioner Ray Kelly. When confronted, Kelly added, the suspect confessed, expressing "remorse" and "relief."
Police said they had no reason to believe there were signs of sexual abuse, but homicide experts say authorities may be holding back.
"Hernandez certainly doesn't present as an organized killer," said Jack Levin, a professor of criminology from Northeastern University.
"It looks like his crime was spontaneous rather than methodically planned," he said. "Based on statistics concerning abductions by strangers and acquaintances, I would speculate that his motivation involved a sexual assault."
Despite stereotypes to the contrary, the recidivism rate among sexual predators is among the lowest, according to Levin.
"It is conceivable that Hernandez never again molested a youngster," he said. "This is particularly likely in light of his confession."
Feelings of remorse and empathy -- not typical in a sociopath -- might have kept Hernandez from repeating his behavior as he matured, he said.
The cold case was reopened in 2010 and, in April, investigators excavated a basement apartment steps away from Patz's home and the bodega where Hernandez said he killed the boy.
The new focus on the case led one of Hernandez's family members or a friend to alert police that they suspected Hernandez's involvement.
His neighbors in Maple Shade, N.J., said he led a quiet life and belonged to a Pentacostal Church, according to The New York Times.
Though Hernandez doesn't seem to fit the typical profile of a child killer, pegging a suspect into a psychological box can be misleading, according to according to Ken Lanning, a former special agent in the Behavioral Science Unit at the National Center for the Analysis of Violent Crime.
"It's complex, and no two cases are alike," said Lanning, who said he, too, doesn't know all the facts in the case. "But [police] must have a reason to believe his story."
Both Levin and Lanning warned about "false confessions."
"People come forward to confess because of publicity and notoriety," said Lanning. "Over the years, there have been two or three in-depth scenarios where someone claimed to be involved in the Etan Patz case."
For a decade, the prime suspect in the case was Jose A. Ramos, a former mental patient now imprisoned for molesting a boy in Pennsylvania. But he told police that he never killed the boy and put him on a subway.
"The police don't just believe people," said Lanning. "They must have some kind of standard to give this guy credibility. Most significant in a case like this is when a guy says, 'I can take you to the body.'"
But in Etan's case, police say it's "unlikely, very unlikely," that they would ever be found.
Hernandez reportedly told police he put the body in the trash, where it would have ended up in a city landfill.
"That can be a mess -- even a week later -- depending on the garbage and how it's compacted," said Lanning. "Especially 33 years later."