For prosecutors, the work is just beginning after the astonishing arrest last week of a man who police say confessed to strangling a 6-year-old New York City boy 33 years ago in one of the nation's most bewildering missing children's cases.
Pedro Hernandez, 51, was charged with second-degree murder in the 1979 death of Etan Patz, based largely on a signed confession he gave after he spoke voluntarily to detectives for hours, according to police.
But to convince a jury beyond a reasonable doubt, prosecutors need more than the confession, even though corroboration isn't necessarily required by law, legal experts say. Piecing together that supporting evidence may be difficult: There's no body and no physical evidence, plus a history of famous false confessions in other high-profile cases.
"We live in a day of CSI, fingerprinting, DNA, hand samples, and foot prints and treads on bottoms of shoes and boots. There's going to be none of that here, and that's tough," said Arthur Aidala, a former prosecutor who is now a criminal defense attorney. "You're essentially relying on this guy's own words, and whether he's credible."
False confessions are common and happen for many reasons, said James Cohen, a law professor at Fordham University, "whether it's that someone is coerced, scared, or is just a wacko looking for 15 minutes of fame."
Among the most well-known was John Mark Karr, who in 2006 said he killed JonBenet Ramsey, the 6-year-old beauty queen found dead in her parents' Boulder, Colo., home a decade earlier. Karr was whisked from Thailand, where he was teaching, to Colorado and was arrested, but he was released after prosecutors concluded he couldn't have killed her. The case remains unsolved.
In the 1930s, more than 200 people came forward to confess to kidnapping the infant son of Charles Lindbergh, the famous aviator. And in the 1980s case of the Central Park jogger, teenagers who initially confessed to the 1989 rape and beating of a woman were later exonerated after DNA evidence and another confession implicated someone else.
The likelihood of DNA evidence emerging in Etan's case is slim. According to police, Hernandez said he lured the boy from his school bus stop on May 25, 1979, with the promise of a soda, then strangled him in the basement of the neighborhood convenience store where he worked, put the body in a plastic bag, walked it around the block and dumped it. The shop has long been renovated into an eyeglasses store, and the body was never found.
But, legal experts say, supporting evidence could be as simple as the fact that Hernandez worked as a stock clerk at the corner store when the boy went missing, and that he told his family and others as early as 1981 that he had "done a bad thing" and killed a child in New York. Investigators are interviewing Hernandez's family and friends, as well as others who knew him back then.
"This is the beginning of the legal process, not the end," Manhattan District Attorney Cyrus R. Vance, Jr. said. "There is much investigative and other work ahead, and it will be conducted in a measured and careful manner."
Etan's disappearance helped foster an era of anxiety about leaving children unsupervised. The investigation at the time was tireless. Thousands of fliers were handed out, publicity was nationwide and dozens of people were interviewed.
Hernandez, then 18, was listed in police paperwork as having been an employee in the neighborhood, but he was never questioned, police said. He slipped away days after the boy vanished, eventually moving to Maple Shade, N.J., where he lived with his wife and daughter before his arrest Thursday. His name did not surface when authorities were excavating a basement down the street from the old shop just weeks ago.
Hernandez was being held Sunday at Bellevue Hospital Center's psychiatric ward. At his arraignment Friday, his court-appointed attorney, Harvey Fishbein, said his client was schizophrenic, bipolar and had been on medication for some time.
A psychiatric evaluation was ordered. No plea was entered, and Fishbein has given no indication that he may try to argue his client is not guilty by reason of mental disease or defect. Defense attorneys not involved in the case say Fishbein must carefully evaluate the confession to ensure it wasn't coerced.
"Someone who isn't sane, that's exactly the type of person who would latch onto the 15 minutes of fame," attorney Joseph Tacopina said. "You have to be very careful that you have the right individual, despite the quest to have resolution that has really tormented the family and city for three decades."
The case is another high-stakes prosecution for Vance, who met with Etan's parents, Stan and Julie Patz, while running for office in 2009 and pledged a fresh look at the investigation.
He presided over attempted rape charges against French diplomat Dominique Strauss-Kahn last year that later crumbled when prosecutors lost faith in the credibility of the hotel maid who claimed he'd attacked her when she came to clean his room.
Linda Fairstein, a former prosecutor in the Manhattan district attorney's office, said Vance acted properly in the Strauss-Kahn case, and is confident he'll do the same now.
"I know how well and thoroughly this investigation was handled in the office when it happened in 1979," she said. "I know that throughout all these decades, every time there has been a suspect, a lead that turned out to be false, each lead was treated as though it could be real."
But no one was ever arrested before.
Etan was declared legally dead by his father more than a decade ago so he could sue convicted child molester Jose Ramos in the boy's death. Ramos had loose ties to the family when he vanished. He was found civilly liable in 2004, largely because he declined to participate in the litigation.
The judgment wouldn't automatically be voided, even if someone else was convicted, but it could provide an opening for Ramos to ask a court to review the finding or for the Patz family to do the same in the interest of suing a new suspect, experts said.
Associated Press Writers Jennifer Peltz in New York City and Michael Virtanen in Albany, N.Y., contributed to this report.