By JENNIFER PELTZ, Associated Press

NEW YORK (AP) — The man convicted in the 1979 killing of 6-year-old Etan Patz was awarded a new trial Monday as a federal appeals court overturned the guilty verdict in one of the nation’s most notorious missing child cases.

Pedro Hernandez has been serving 25 years to life in prison since his 2017 conviction. He had been arrested in 2012 after a decades-long, haunting search for answers in Etan’s disappearance, which happened on the first day he was allowed to walk alone to his school bus stop in New York City.

The appeals court said the trial judge gave a “clearly wrong” and “manifestly prejudicial” response to a jury note during Hernandez’s 2017 trial — his second. His first trial ended in a jury deadlock in 2015.

The court ordered Hernandez’s release unless the 64-year-old gets a new trial within “a reasonable period.”

The Manhattan district attorney’s office, which prosecuted the case, said it was reviewing the decision. The trial predated current DA Alvin Bragg, a Democrat.

Harvey Fishbein, an attorney for Hernandez, declined to comment when reached Monday by phone.

A message seeking comment was sent to Etan’s parents. They spent decades pursuing an arrest, and then a conviction, in their son’s case and pressing to improve the handling of missing-child cases nationwide.

Etan was among the first missing children pictured on milk cartons. His case contributed to an era of fear among American families, making anxious parents more protective of kids who many once allowed to roam and play unsupervised in their neighborhoods.

The Patzes’ advocacy helped establish a national missing-children hotline and made it easier for law enforcement agencies to share information about such cases. The May 25 anniversary of Etan’s disappearance became National Missing Children’s Day.

Etan’s case spurred a huge search and an enduring, far-flung investigation. But no trace of him was ever found. A civil court declared him dead in 2001.

Hernandez was a teenager working at a convenience shop in Etan’s downtown Manhattan neighborhood when the boy vanished. Police met him while canvassing the area but didn’t suspect him until they got a 2012 tip that he’d made remarks years earlier about having killed a child in New York.

Hernandez then confessed to police, saying he’d lured Etan into the store’s basement by promising the boy a soda and choked him because “something just took over me.” He said he put Etan, still alive, in a box that he left with curbside trash.

Hernandez’s lawyers said his confession was false, spurred by a mental illness that makes him confuse reality with imagination. He also has a very low IQ.

The trials happened in a New York state court. Etan’s appeal eventually wound into federal court and came to revolve around Hernandez’ police interrogation in 2012.

Police questioned Hernandez for seven hours — and they said he confessed — before they read him his rights and started recording the interrogation. Hernandez then repeated his admission on tape, at least twice.

During nine days of deliberations, jurors sent repeated queries about those statements. The last inquiry asked whether they had to disregard the two recorded confessions, if they concluded that the first one — given before the Miranda warning — was invalid.

The judge said no. The appeals court said the jury should have gotten a more thorough explanation of its options, which could have included disregarding all of the confessions as improperly obtained.

Associated Press writers Larry Neumeister in New York and Eric Tucker in Washington contributed.