NEW YORK — A law enforcement official said Thursday that a man has told police that he suffocated Etan Patz, the 6-year-old boy whose disappearance on his way to school in 1979 helped give rise to the missing-children’s movement that put youngsters’ faces on milk cartons.

Pedro Hernandez was picked up late Wednesday in New Jersey, according to a law enforcement official, and was being questioned Thursday by the Manhattan district attorney’s office.