After 18 days of deliberations that included lengthy testimony read back, dozens of pieces of evidence and a computer spreadsheet to keep it all straight, the jury in the 1979 disappearance of Etan Patz surrendered in an agonizing stalemate: 11-1.

The holdout says he just couldn't be convinced of a former stock clerk's confession to choking the 6-year-old and dumping his body a few blocks away.

"I couldn't get there," Adam Sirois, juror No. 11, said Friday after the judge declared a mistrial in Pedro Hernandez's murder trial. Sirois said Hernandez's mental health history "was a huge part of this case," and he couldn't stop wondering about the roughly seven hours police questioned him before administering his Miranda rights and turning on a video camera.

Hernandez, 54, of Maple Shade, New Jersey, confessed in 2012 to killing Etan, a case that has confounded authorities for decades. He said he lured the first-grader to the basement with a promise of a soda, where he choked him and then dumped the body a few blocks away. His lawyers said Hernandez is mentally ill and the confession was fiction. They blamed another longtime suspect.

Etan's body was never found — nor was any piece of his clothing or backpack. Hernandez said he tossed the bag behind a freezer in the basement, but the store was closed a few years later and cleaned out.

Jurors first decided whether they believed the boy had been kidnapped and killed, said Jennifer O'Connor, juror No. 10. "Which we all agreed to without a body," she said.

They then turned their attention to the missing bag.

"When I think back to 1979, it's not the days of advanced technology," O'Connor said. " ... Things were just done differently, so I was able to find it plausible as to why they didn't find the bag."

Jurors deliberated after 11 weeks of testimony and said they were deadlocked twice. They were split 8-4 on the first vote to convict, then they were 6-6, 9-3, 10-2, and then finally 11-1 on Friday, they said.

Juror No. 7, Doug Hitchner, said he at first wanted to acquit but changed his mind as deliberations progressed. "What worked for me was to try to make the argument publicly to the other jurors," he said. He was one of two voting to acquit until Friday.

During deliberations, jurors had days of testimony read back to them. They created spreadsheets with timelines, went over dozens of pages of notes taken during the trial and tracked evidence of Hernandez's mental health.

"We had 12 jurors, each one of them who contributed at a high intellectual level," said Edwin Thompson, juror No. 4, who works in real estate. "Every one of us had something to say, and as the case progressed, I was learning things."

Many of the jurors encouraged prosecutors to retry the case. A hearing was set for June 10.

"I'm very sad we could not get a resolution for the case, for the Patz family, for the Hernandez family, for the city of New York, but we really tried our hardest and I don't think we could have done any more," O'Connor said.

Jury forewoman Alia Dahhan had stronger words: "They'll get him next time. Pedro Hernandez, you know what you did."