Shot of Opportunity to be used in Oregon "Rules of Engagement"

Law enforcement snipers, commonly called police snipers, and military snipers differ in many ways, including their areas of operation and tactics. A police sharpshooter is part of a police operation and usually takes part in relatively short missions. Police forces typically deploy such sharpshooters in hostage scenarios. This differs from a military sniper, who operates as part of a larger army, engaged in warfare. Sometimes as part of a SWAT team, police snipers are deployed alongside negotiators and an assault team trained for close quarters combat. As policemen, they are trained to shoot only as a last resort, when there is a direct threat to life; the police sharpshooter has a well-known rule: "Be prepared to take a life to save a life." Police snipers typically operate at much shorter ranges than military snipers, generally under 100 meters (109 yd) and sometimes even less than 50 meters (55 yd). Both types of snipers do make difficult shots under pressure, and often perform one-shot kills.

A US Secret Service sniper on the roof of the White House
Police units that are unequipped for tactical operations may rely on a specialized SWAT team, which may have a dedicated sniper. Some police sniper operations begin with military assistance. Police snipers placed in vantage points, such as high buildings, can provide security for events. In one high-profile incident, Mike Plumb, a SWAT sniper in Columbus, Ohio, prevented a suicide by shooting a revolver out of the individual's hand, leaving him unharmed.

A U.S. Coast Guard TACLET marksman uses an M107 from a helicopter.
The need for specialized training for police sharpshooters was made apparent in 1972 during the Munich massacre when the German police could not deploy specialized personnel or equipment during the standoff at the airport in the closing phase of the crisis, and consequently all of the Israeli hostages were killed. The German police only had regular police who were selected if they engaged in hunting as a hobby. While the German army did have snipers in 1972, the use of snipers of the German army in the scenario was impossible due to the German constitution's explicit prohibition of the use of the military in domestic matters. This lack of trained snipers who could be used in civilian roles was later addressed with the founding of the specialized police counter-terrorist unit GSG 9.