'If gun control worked Chicago should be safe'
Gingrich gets in a zinger, but a former prosecutor also shows how the DC gun ban actually increased the number of murders because victims were left defenseless. After the gun ban went into effect the murder rate climbed from 188 to 454 by 1993. The rate had begun to go down but it dropped dramatically after the courts overturned the gun ban and was 88 in 2012. The fact is that gun bans only help the crooks because they are crooks and don't care what the law is while the innocent are made defenseless.
You also should remember that police are a reactive force for the most part. They will show up at a murder scene to try to figure out who did it but they lack a deterrent effect. But the fear of attacking someone who can defend themselves is a deterrent effect.