A federal appeals court on Monday ordered that a man convicted in the disappearance of 6-year-old Etan Patz in 1979 should receive a new trial or be released.

The man, Pedro Hernandez, was convicted of murder in 2017 after he confessed to luring Etan into a basement as he walked to his school bus stop alone in SoHo and attacking him.

Mr. Hernandez was charged by the Manhattan district attorney’s office, with his first trial in 2015 ending in a hung jury. In 2017, a Manhattan jury convicted Mr. Hernandez on the ninth day of deliberations, after which the jury foreman said “deliberations were difficult.”

Mr. Hernandez’s lawyers had argued in the appeal that the trial court’s instructions to the jury were improper and prejudiced the verdict.

“We conclude that the state trial court contradicted clearly established federal law and that this error was not harmless,” a three-judge appeals panel held in a ruling on Monday.

Efforts to reach the Manhattan district attorney’s office for comment were not immediately successful.

This is a developing story and will be updated.