A crime prevention method or deterrent was any means of keeping crime from occurring.
In 2373, Neelix noted that Bahrat's space station's cryostatic prison wasn't an effective deterrent against narcotics trafficking, as the Kolaati had been doing it for years without being noticed. (VOY: "Fair Trade")
In 2374, Tuvok expressed an interest in learning about crime prevention methods on the Mari homeworld. Nimira offered to share them if he would allow her to visit USS Voyager, so as to learn about their methods. (VOY: "Random Thoughts")