You're assuming that all honest people want to naturally kill other people when they're mad at them. If that were the case, crime rates would be astronomically high regardless if guns existed or not. If person A gets mad at person B and desires to kill them, they'll find a way to kill them. If they don't have a gun, then they'll use a knife, or a bat. Hell, they'll use their bare hands if they have to.

Honest people don't kill other people unless they feel their own lives are threatened. Criminals by definition do not follow the law, so by outlawing guns, only outlaws will have guns. What you effectively do is remove the gun from the honest person desiring to protect themselves, and arm the criminal with bad intent. The honest person is left defenseless.

Case in point: "Shooting incidents in London have almost doubled compared with the same period last year, prompting grave concerns that gun crime in some areas is out of control." [0]

Aren't guns illegal in England? How are people then getting shot, by guns, in a city where guns are illegal? Again, because criminals by definition don't follow the law and will find a way to get a gun regardless.

[0]: http://www.theguardian.com/uk/2009/nov/03/london-gun-crime-s...