(CBS/AP) NEW YORK - Pedro Hernandez, the man accused of killing 6-year-old Etan Patz in 1979, pleaded not guilty Wednesday and claimed that the boy was still breathing when he last saw him, according to new details of his alleged confession.
Police said Hernandez, 51, confessed in May to killing Etan, but the suspect answered "not guilty" during his hearing as his lawyer insisted his confession to police was false.
Defense attorney Harvey Fishbein said outside court his client "had no motive and no history."
"There is a serious question as to what happened in May 1979," Fishbein said. "There is no crime scene. There are no witnesses to a crime."
Fishbein also noted a body was never recovered. He said that Hernandez confessed falsely after seven hours of questioning by police and that he is still under medical and psychiatric care.
"My client is not happy that he is in jail," Fishbein said.
Hernandez was a teenage stock clerk at a convenience store close to the bus stop where Etan was headed when he went missing on his way to school on May 25, 1979.
Etan's disappearance sparked an intensive and heavily publicized search that turned May 25 into National Missing Children's Day. His photo was among the first put on milk cartons.
Police approached Hernandez this spring based on a tip that came after federal authorities and police dug up a basement in the neighborhood hoping for clues. Hernandez is now married father with no criminal record living in Maple Shade, N.J.
Investigators said Hernandez told them he lured the boy into the basement of the convenience store where he choked him and left his body in a cardboard box in a bag of trash about a block away.
According to a videotaped statement by Hernandez, when he left the box, Etan was alive, his lawyer said in court papers.
Fishbein said he would seek to dismiss the case because the only evidence is his client's false confession. Under state law, a confession can be enough to convict someone as long as authorities can establish a crime occurred and the confession is reliable.
Fishbein said if the case goes forward the defense will revolve around his client's mental state, though he isn't pursuing an insanity defense and Hernandez was found mentally fit to stand trial.
An insanity defense would mean acknowledging he committed the crime but arguing that he was too psychologically ill to know it was wrong. Hernandez didn't kill Etan and made a false confession because of his mental problems, among other factors, Fishbein said.
"The only part that mental disease plays in this case is its role in the confession," he said before the court date.
Psychiatric exams of Hernandez have found that he has an IQ in the borderline-to-mild mental retardation range, his lawyer has said. Hernandez also has been found to suffer from schizotypal personality disorder, which is characterized by hallucinations, according to his lawyer.