The prime suspect in the disappearance of Etan Patz over two decades ago will not face criminal charges, say Manhattan prosecutors.

Six-year-old Patz vanished from a street in SoHo in 1979. His case prompted a nationwide effort to recover missing children, including the practice of printing faces on milk cartons.

Prosecutors say they do not have enough evidence to get an indictment against 58-year-old Jose Ramos, who is currently serving a 20-year sentence in Pennsylvania on unrelated pedophile charges. However, the investigation remains open, and charges could eventually be filed if more evidence is uncovered.

Ramos, the boyfriend of Patz’ babysitter, has admitted to trying to molest a boy who looked like Patz the day he disappeared.

The boy’s father, Stanley Patz, had been pushing for criminal charges and is also pursuing his own wrongful-death lawsuit against Ramos.

Etan Patz was legally declared dead last summer.