Actually i would argue differently. The percentage of gun related deaths would have to be much probably over 90% to prove what you are saying. If you would say most, or close to all murders are gun related and the rest were not then it would mean that the release of more guns would add to the total homicide. The fact that only 30% is gun related proves that one with an intent to kill will kill even without a gun.
Canadas culture/ environment is totally different then ours. I dont believe they have the same immigrant problem like we do.