The jury deliberated for about a half-hour before delivering the verdict against 29-year-old Christopher Johnson, of Fairfield.
Adams County District Attorney Shawn Wagner intends to seek the death penalty when the sentencing phase begins Tuesday afternoon.
Defense attorneys had acknowledged that Johnson fatally shot Wildlife Conservation Officer David Grove in November 2010. But they had argued for third-degree murder, saying Johnson was too drunk to form the intent to kill.
Investigators say Johnson and a friend had poached a deer at night when Grove pulled them over on a dark stretch of rural road near Gettysburg. Johnson, though, was not allowed to have gun because he was a convicted felon.
The passenger testified that a shootout began after Johnson vowed he wouldn’t go back to prison. Jurors were told the two men fired 25 shots in the exchange that left Grove dead and Johnson injured.
A doctor who treated Johnson’s wounds said the defendant told him he drank 12 beers the day of the shooting.
Jurors were brought in from neighboring Lancaster County because of the publicity surrounding the case. Grove was the first Pennsylvania game warden killed in the line of duty in 95 years, and more than 1,000 mourners attended his funeral.