A convicted cop killer sentenced to life in prison for his role in the death of a New Jersey state trooper nearly 40 years ago has died in federal prison.

Thomas William Manning, 73, was convicted in the killing of Trooper Philip Lamonaco in December 1981.

Lamonaco died during a gun battle on Route 80 in Warren County after a traffic stop involving Manning and his accomplice Richard Charles Williams. It is believed that Williams shot the trooper nine times, leaving him face down in the snow.

They were arrested in 1985, tried and convicted.

"For law enforcement, it was a phenomenal investigation. Maybe the best collaborating efforts we've ever seen between state police with FBI and various state police agencies,” says State Police Col. Patrick Callahan. “It took us a few years to find them but we finally did, tried them and brought to justice."

Williams died in prison in 2005.

Manning was also sentenced to more than 50 years in prison for a series of bombings in New York.

Lamonaco was 32 years old when he died. He left behind a wife and three children. One of his sons is now a state trooper.