The Old West's Dodge City Kansas saw many fewer murders-per-year in its wildest days than take place in Chicago, New York City, Detroit, or Washington DC on your average Weekend. I learned at Military Police School way back in 1969 that evil people do evil things, and the Police can only keep score. Prevention is Fantasy. You catch as many as you can after the ACT, and you pray the Evil Doers encounter an Armed Individual during their Next ACT. It makes keeping score much easier to find the Bad Guy dead at the scene, killed in self-defense by a Law-Abiding-Citizen.