Defense lawyers said Pedro Hernandez, 51, has schizophrenia and a history of hallucinations and it's unclear how much that will factor in the case charging him with the 1979 murder of young Etan Patz.
But if his psychiatric record becomes an issue, he'll encounter a justice system that seeks to strike a balance between recognizing mental illness and holding people responsible for their actions - a balance that has shifted back and forth over more than a century and a half.
Meanwhile, Etan's father made clear that the attention to the case since Hernandez's arrest last week had taken a toll, telling reporters they had "managed to make a difficult situation even worse."
"It is past time for you to leave me, my family and my neighbors alone," Stan Patz said in a note posted on his apartment building's door.
Authorities on Tuesday continued to try to flesh out the man's startling admission in a case that galvanized the movement to publicize the problem of missing children.
Police encountered Hernandez, who worked in a nearby convenience store, shortly after Etan vanished on his way to school on May 25, 1979. But investigators never considered Hernandez a suspect until a tipster pointed them his way this month, saying he had made incriminating statements. He responded with an emotional and gruesome confession: He said he strangled the boy, hid his body in a bag and a box and dumped it near some trash, police said.
His statements launched police and the Manhattan district attorney's office into a complex process of building a 33-year-old case with, so far, no physical evidence.
And it has started the courts on a parallel path of exploring Hernandez's mental health. After defense lawyer Harvey Fishbein told a judge that Hernandez was schizophrenic, bipolar, had had visual and auditory hallucinations, and had been on psychiatric medication for some time, the judge ordered an examination to see whether he was mentally fit to stand trial.
The results aren't yet known, and either side could challenge the findings and get another exam. It will ultimately be up to a judge to declare whether Hernandez can go to trial. If not, he would be sent to a psychiatric hospital and evaluated periodically to see whether he had improved enough to go to court. Most people found unfit are eventually returned to court, legal experts say.
Such exams aim to assess whether someone is well enough to participate in a trial and aid his or her own defense. They are separate from an insanity defense, which revolves around the defendant's psychological state at the time of the alleged crime.
In New York and many other states, defendants have to prove they were so mentally ill that they didn't know what they were doing was wrong. If successful, they are sent to psychiatric hospitals until judged well enough for release, if ever.
Fishbein declined to comment Tuesday on whether he might pursue an insanity defense. It could be challenging to portray Hernandez's mindset so long ago, potentially involving digging up decades-old medical records, tapping friends' and relatives' memories of his behavior at the time, or both.
"The closer you can bring his mental health and treatment issues to the time of the crime, the more plausible it becomes that he was suffering from mental disorder at the earlier time," said Stephen J. Morse, a University of Pennsylvania law and psychiatry professor who's not involved in the case.
One of Hernandez's sisters, Norma Hernandez, said Tuesday that she went to police in Camden, N.J., years ago to report a rumor he had confessed at a prayer group. Camden police declined to comment on her remarks.
Contributing to this report were Associated Press writers Tom Hays and Colleen Long in New York, Samantha Henry in Camden, N.J., and Patrick Walters in Philadelphia.
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