BETHLEHEM, Pa. (AP) — The man rocked side-to-side as he muttered incoherently with a knife in his hand. Every few minutes he looked up and grunted at the police officer in the doorway talking with him. After the sixth time the officer told him to put down his knife, the man suddenly raised it and stepped toward the officer, who was about 12 feet away. The officer fired, killing him. At that point in the story, Pennsylvania State Police Cpl. Keven Selverian stopped. He had questions for those listening to the real-life incident. Was the officer justified in using deadly force under those circumstances?