ALBANY, N.Y. — A man who shot and killed a New York state trooper more than 40 years ago is free on parole after a police union’s efforts to keep him in prison failed.

Seventy-four-year-old John Ruzas was released Monday from Fishkill Correctional Facility in the Hudson Valley. He had been sentenced to 25 years to life for killing Trooper Emerson Dillon and was granted parole last month after numerous rejections.

Dillon was gunned down in 1974 after he had pulled over Ruzas’ vehicle on the Thruway in central New York. Ruzas and another man had just robbed a jewelry store near Syracuse when Dillon stopped their vehicle.

Ruzas was granted parole after a judge ordered the state board to hear his case. The troopers’ union opposed his release.

State officials say Ruzas is living on Long Island.