The 1979 disappearance of Etan Patz helped catalyze a national missing-children’s movement. The 6-year-old was one of the first children whose disappearance was publicized in what became a high-profile way: on milk cartons.

The conviction of Pedro Hernandez, the SoHo bodega clerk found guilty in the 1979 kidnapping and murder of 6-year-old Etan Patz, was overturned by a federal appeals court Monday — reopening the book on one of the city’s most notorious slayings.

Pedro Hernandez was sentenced to 25 years after confessing to kidnapping and killing Patz in New York City, in notorious 1979 child disappearance case.