A Pennsylvania judge has denied a pair of defense requests that sought to prevent prosecutors from seeking the death penalty against a man charged with fatally ambushing a state police trooper near a rural barracks.

Attorneys for Eric Frein had said the death penalty option was unconstitutional. A Pike County judge rejected the claims on Friday.

Frein is charged with fatally shooting Cpl. Bryon Dickson II and wounding another trooper in September 2014.

He led police on a tense 48-day manhunt before U.S. marshals caught him about 30 miles from the shooting scene. Frein has pleaded not guilty.

Court documents say Frein spoke of wanting to start a revolution in a letter to his parents and called Dickson's slaying an "assassination" during a police interview.