(REUTERS) -- Jurors in the New York murder trial of a man who confessed to killing 6-year-old Etan Patz decades ago will return on Thursday for a 12th day of deliberations after a judge refused to accept the panel's claim that it was unable to reach a verdict.

The jury, which is weighing kidnapping and murder charges against Pedro Hernandez, on Thursday will begin rehearing closing arguments from both the prosecution and the defense. That process is expected to take until Friday.

Patz's 1979 disappearance from his Soho neighborhood in Manhattan brought national attention to the issue of missing and abducted children. He was one of the first children whose pictures appeared on milk cartons in an effort to locate them.

In 2012, Hernandez, a 54-year-old former deli worker, confessed to police that he had choked Patz, stuffed him in a box and left his still-moving body in an alley. But his defense attorneys had argued that Hernandez is mentally ill and his confession was coerced by police.

On its 11th day of deliberations on Wednesday, the jury in state Supreme Court in Manhattan sent a note to Justice Maxwell Wiley asking to rehear the lawyers' summations. But before the judge could answer, the panel sent a second note saying it was deadlocked.

"We the jury after 10 days of deliberation, want the court to know that we are unable to reach a unanimous decision," the note read.

Wiley ordered the panel to keep working, and agreed to allow the reading of closing arguments, which took lawyers two days to deliver during the trial.

The defense, hearing that the jury had said it was deadlocked, moved for a mistrial. The judge denied the motion.

Patz vanished on May 25, 1979 as he walked alone for the first time to a school bus stop. The crime long haunted New Yorkers who can recall the massive search for the missing blond boy, who was never found. He was declared dead in 2001.

Hernandez's defense attorneys have put the blame for the boy's disappearance on Jose Ramos, who dated a Patz family babysitter and was long considered the prime suspect.

Ramos is serving a prison term after being convicted of sexually abusing boys.

During closing arguments, prosecutors used PowerPoint slides to show jurors quotes from witness testimony, as well as photographs of the alleged crime scene.

Defense lawyers also presented exhibits from the trial, including photographs of the store where Hernandez worked, police documents from the 1979 search for Patz and excerpts of the video confession made by Hernandez.

If the jury stalemate holds and a mistrial is declared, the prosecution will have to decide whether to retry the case.