Case of Patz Killing Suspect Goes to Grand Jury A grand jury in Manhattan has begun hearing evidence against the man who confessed to killing Etan Patz, a 6-year-old, in 1979, the first direct indication that prosecutors have decided to move forward with a murder prosecution after months of investigating the man's claims, people briefed on the matter said Tuesday. The confession by the man, Pedro Hernandez, in May upended three decades of investigations into other leads in the case, among the most publicized missing-persons investigations. While the case file comprised stacks of boxes, it held nothing of value on Mr. Hernandez, 51, who had never been a suspect. To allow both sides more time to investigate, Cyrus R. Vance Jr., the Manhattan district attorney, and Mr. Hernandez's lawyer, Harvey Fishbein, repeatedly agreed to stall the clock that would generally require the case to be presented to a grand jury within six days of an arrest. The last delay set a deadline of this Thursday. It is not clear whether the investigations in the months since Mr. Hernandez's arrest have yielded evidence to corroborate his confession, which is typically needed to win a conviction. But law enforcement officials have maintained that the videotaped confession itself is strong and buttressed by confessions Mr. Hernandez made to others years ago. If the grand jury indicts Mr. Hernandez, the trial would be challenging. Mr. Fishbein has said that Mr. Hernandez has a long history of mental illness that includes diagnoses of schizophrenia and bipolar disorder, with visual and auditory hallucinations. His mental health history could be used to raise doubts about the reliability of his confession. Mr. Hernandez, who was 18 at the time Etan vanished, worked as a stock boy in a bodega at 448 West Broadway, which is now an eyeglass store. Etan disappeared on the first morning his parents allowed him to walk the two blocks alone from the family's home on Prince Street in SoHo to a school bus stop on West Broadway. Mr. Hernandez was working in the store's basement, which had a separate door to the street. The police have said he told them that Etan was at the bus stop when Mr. Hernandez lured him to the basement by promising him a soda. In announcing Mr. Hernandez's arrest in May, Police Commissioner Raymond W. Kelly expressed confidence that the case had been solved. "He was remorseful, and I think the detectives thought that it was a feeling of relief on his part," Mr. Kelly said at the time. We believe that this is the individual responsible. But Mr. Vance was more circumspect. During an unrelated news conference in early June, Mr. Vance declined to say whether he was confident that Mr. Hernandez was the killer because he said it was premature. "We need to make sure that accountability is levied as to the right person, and under appropriate evidence," Mr. Vance said. Mr. Vance declined to comment on the grand jury on Tuesday, as did Mr. Fishbein. The man once seen as the primary suspect in the case was briefly released from prison last week before being rearrested. Jose A. Ramos, a convicted sex offender, had been required to provide the address where he would be residing, but the decades-old one that he gave for a cousin in the Bronx was no longer accurate. Mr. Ramos, 69, had served the maximum sentence of 27 years after being convicted of sexually abusing a boy. Although he was a suspect in Etan's disappearance, he was never charged. William K. Rashbaum contributed reporting.