A high-ranking New York City Police Department officer died after a self-inflicted gunshot wound to the head.

Deputy Chief Steven Silks was found in an unmarked patrol car wearing civilian clothes Wednesday evening, just one month before he would turn 63 and face mandatory retirement. He had shot himself in the head, with the gun reportedly discovered beside him. He was rushed to the hospital but couldn’t be saved.

A fellow officer told the New York Daily News that Silks was deeply committed to the job. Silks reportedly submitted his mandatory retirement papers the day before.

“His family lives out of state. He’s not married. He absolutely lived for the NYPD,” the officer said. “He was admired and loved by everybody he worked with. He was aged out. He’s the kind of guy who would have served until he died of natural causes.”

Sources within the NYPD said Silks had expressed sadness ahead of his mandatory departure from the force. He had served the force for 39 years.