( CNN) The bodega clerk convicted for the 1979 assassination of New York first-grader Etan Patz was sentenced on Tuesday to 25 years to life in prison.

Pedro Hernandez, 56, was convicted of kidnapping and assassination in February, virtually 40 years after the 6-year-old disappeared on May 25, 1979.

Etan left home to walk to a school bus stop and was not seen again. In the early 1980 s, his photo appeared on milk cartons across the country, the first time the method was used to try to locate missing children.