A man known for his extensive history of mental health issues was shot and killed by an off-duty police officer while holding a realistic-looking BB gun outside a well-known Staten Island diner on Friday night, as per sources and the NYPD.

Bullets flew just after 8 p.m. at the well-known Andrew’s Diner on Hylan Boulevard in Eltingville, according to the NYPD.

Diners alerted cops that a man with a gun was menacing the eatery, according to sources.

The armed man, identified by sources as 44-year-old Jesse Campbell, engaged in a confrontation with two off-duty NYPD officers near the diner, during which he aimed the replica weapon at them, sources reported.

Police have not yet confirmed the man’s name.

Amidst the altercation, a female detective from the Internal Affairs Bureau, who was one of the off-duty officers, discharged several rounds at the man, hitting him multiple times, according to the NYPD and sources.

Police have a video that showed off-duty officers giving Campbell instructions to drop the gun before the fatal shooting, according to sources.

Campbell was taken to Staten Island University Hospital, where he was pronounced dead, sources said.

Campbell had “significant” mental health issues, sources said, adding that he had allegedly told his mother and sister earlier in the day that he intended to be killed by police.

“It looks like suicide by cop,” a police source said.

A hyper-realistic BB gun was recovered at the scene, according to sources and the NYPD.