Unintentional discharges (UDs) of firearms present a challenge to law enforcement in that they occur unexpectedly and infrequently, yet they can lead to property damage, injury, and death. Previous research has identified that UDs may occur due to a sympathetic muscle contraction, loss of balance, or a startle reaction. It has been suggested that training officers in various situations might reduce UDs. However, some officers (20 percent) trained in various situations continue to place their finger on the trigger without awareness after the training.

While engaging in strenuous activities (e.g., destabilization, jumping, kicking, and pulling or pushing bars and pulleys) at maximum and sub-maximum intensity, some officers may exert enough force to overcome the trigger weight of a cocked firearm (4 to 6 pounds) and even an uncocked firearm (8 to 12 pounds). UDs might be likely to occur during strenuous use of the lower limbs (e.g., kicking a door or jumping) or as a result of a loss of balance during such activities. Other researchers have suggested that UDs may be related to complacency (e.g., a shift in attention); drugs (e.g., general impairment of motor functioning); fatigue (e.g., decreased eye-hand coordination); firearm design (e.g., single- and double-action triggers); human error (e.g., skipping a safety step); insufficient training (e.g., lack of skill transfer to the real world); and stress (e.g., bodily trembling).