Police say the off-duty officer drew his 9 millimeter service weapon and shot 23-year-old Atiba Watkins, of Central Islip, once in the torso. Watkins was taken to Stony Brook University Medical Center where he was listed in critical but stable condition.
Police say witnesses said Watkins brandished a knife at the time he was shot. A knife was recovered at the scene. No arrests have been made.
Authorities have not released the officer's name. The Suffolk County District Attorney's Office is investigating. An NYPD spokesman declined comment.
