The longest serving member of the NYPD is being forced to give up his badge later this month, after 44 years of service.

Detective John Roe, 62, joined the department over four decades ago and is a first-grade detective in the 26th Precinct in Harlem — the highest investigative rank.

But like all cops, the Irish American must retire before he reaches the age of 63, on October 31st.

 “I’m angry that there is an age limit, but you can’t fight Father Time,” he told the New York Post.

For the last twenty years, Roe has worked on murders, robberies, burglaries, and assaults, particularly domestic-violence cases.

“I’ve had the most fantastic career. I couldn’t imagine doing anything else,” he said.

He was sworn in as a cop in November 1970 and went to work in the 40th Precinct. In his 44-year career, he estimates he has made more than 1,000 arrests and played a part in double that amount.

The detective doesn’t carry a standard-issue 9 mm Glock semiautomatic, instead he opts for an old-time “six-shooter” — a .38-caliber Smith & Wesson Model 10. He also straps a five-shot Smith & Wesson to his ankle. 

Despite carrying two guns on the beat every day of his work life, he has only ever had to use his guns on the firing range.

Already drawing from his decades of experience, Roe has collaborated on a new e-book “Bronx Requiem,’’ which is available next month.

“It’s about a stag party where this girl is killed and they accuse this cop of her murder. The cop winds up hanging himself, and his partner goes about trying to clear his name,” he said.

Roe admits to being ‘computer illiterate’, despite having a computer and printer on his desk, he prefers pen and paper.

“People tell me about retirement, ‘It’ll be good for you,’” he said. “I tell them, ‘It’s good for everyone else. Not for me.’”

His last official day is October 26, when he will have a ceremonial “walk out” and be saluted by dozens of fellow police officers at Police Headquarters.