An NYPD sergeant was found dead of a suspected self-inflicted gunshot wound Saturday afternoon on Staten Island, law enforcement sources told the Post.

The off-duty transit cop, who works in Brooklyn, was discovered around 2 p.m. at his Richmondtown home by co-workers who became worried when he did not show up for work and decided to check on him, sources said.

The victim is the fifth NYPD cop to take his own life this summer.

The NYPD offers counseling with the Employee Assistance Unit and the Chaplains Unit and also encourages the use of Police Officers Providing Peer Assistance (POPPA), which is separate from the department.