The KKK would be so proud.
Has nothing to do with race. We are producing generations that think nothing of blowing away the innocent because really, there are no adverse consequences to them for their actions. If they are young enough, they go to a juvenile facility, which, at least where I live, is a joke. If they are adults, they are sent to prison where the taxpayers provide them with food, lodging, clothing, medical care, legal counseling and all the other basic and not-so-basic necessities. If they happen to be sentenced to death in states where the death penalty exists, there is a good possibility they will never be executed. And heaven help you as a corrections officer if you look cross-eyed at an inmate. You could be sued and/or lose your job.
The best deterrent is the swift and consistent application of the death penalty. The person executed obviously won't be around to take another innocent life. And the knowledge that if caught, you could be swinging from a rope in the very near future might make you think twice before firing your gun at some innocent bystander.