Users usually view these computer images through a head- mounted device that restricts their vision to two small video monitors. The computer can change the environment based on the user's reaction. Users may also be able to wield virtual weapons against virtual enemies. Some researchers are now experimenting with tactile feedback devices that provide users with a simulated sense of touch. Virtual reality offers law enforcement benefits in the areas of pursuit driving, firearms training, high-risk incident management, incident re-creation, and crime scene processing. Some barriers to virtual reality training include the slow pace at which current computers process large amounts of graphic information, cumbersome equipment, and possible negative psychological effects on users. 15 notes