Portland police say it’s impossible to truly simulate what it feels like to be in the kind of life-or-death situation that can prompt law enforcement officers to use deadly force against the civilians they are sworn to protect. Advertisement Police have spent decades looking for ways to demonstrate to young officers how quickly they need to make decisions about force. In the 1990s, the military and police departments began using the first rudimentary firearms training simulators, called “F.A.T.S”