An ex-Marine who fought in Iraq and was being treated for post-traumatic stress disorder gave a fellow patient some heroin at a Veterans Affairs hospital in New Jersey, then neglected to alert anyone when the man collapsed and died of an overdose, authorities said yesterday.

Ryan Krieger, 28, has been charged with distribution of heroin and obstruction of justice.

He and the other patient, identified only as J.Z., allegedly sneaked out of the VA Medical Center in Lyons to buy heroin in 2011. When they returned, they shared the drug with a third patient, the authorities said.

Members of the hospital staff discovered J.Z. dead in his room later that day.