Sniper opens in October 1998 near Buffalo, NY. A man is alone in the dark in a forest. He clutches an assault rifle and is thinking about his mission. "You can cut holes in the fences around the death camps," he thinks. "A trickle of relief in the abortion holocaust. It is your duty to do it." He nestles the rifle into his shoulder and shoots at  his target through the back window of a house, then flees. Barnett Sepia, a doctor who provides abortions, is fatally wounded.

The shooter is James Kopp, the son of a Marine, who came to embrace the pro-life cause and ultimately the notion of "justifiable homicide: against abortion providers. Kopp fancies himself a lone wolf in the movement; a celibate man driven to "defend the unborn." He is nicknamed "Atomic Dog" in the movement and helps orchestrate assaults on abortion clinics. As the story unfolds, he becomes the central figure in an international manhunt for multiple shootings in Canada. On the FBI''s Top Ten Most Wanted list, Kopp flees to Mexico, Ireland, and France. Award-winning journalist Jon wells followed Kopp''s footsteps, traveled to his hometown, and interviewed investigators in the U.S., Canada, Ireland, and France to tell this gripping detective story and dark psychological drama.