A retired NYPD transit sergeant shot and killed himself Monday on Staten Island, police sources told The Post.

The 48-year-old man, whose name was withheld pending family notification, shot himself in the head while in his car in a transit parking lot on Arthur Kill Road near Richmond Avenue, the sources said.

His death comes amid a spate of suicides by NYPD cops and former officers.

On Aug. 14, veteran NYPD Officer Robert Echeverria shot and killed himself while off duty at his Queens home, the ninth cop suicide this year.

Amid the recent suicides, NYPD Chief of Department Terence Monahan admitted last month that the city’s insurance system makes it tough for cops to seek mental health care.