The Fourth Amendment standard of reasonableness of the level of force is not conducive to a precise definition or mechanical application. Instead, careful attention should be given to the facts and circumstances of each case from the perspective of a reasonable officer at the scene. Decisions by the U.S. Supreme Court have emphasized three factors: (1) the severity of the crime, (2) whether the suspect poses an immediate threat to the safety of the police officers or others, and (3) whether the suspect is actively resisting arrest or attempting to evade arrest by flight. Police agencies should avoid developing overly simple and rigid rules. Instead, they should give careful consideration to crafting guidelines that provide police officers with a range of options within which to make decisions regarding the appropriate level of force in particular situations. They should also provide sustained training sessions that include the practical application of the principles to realistic scenarios to increase officer skill and confidence in making difficult decisions. Photographs and reference notes