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.

Etan Patz disappeared while walking to his Manhattan school bus stop alone for the first time on May 25, 1979. Pedro Hernandez was arrested in 2012. He was convicted of murder and kidnapping in 2017 and sentenced to 25 years to life in prison.