They're doing a slight of hand on you when they talk this way because they sometimes talk about "crime" and mean literally anything that can be charged by the police or civil law - this is what they want to use when they talk about "more enforcement just makes more criminals" because everyone speeds (and tickets don't do shit to stop speeding). But when people talk crime they usually mean property or violent crime caused by niggers, and locking up niggers for doing crimes DOES decrease the crimes done, because there is not an infinite supply of niggers (though they're damn trying).