Why is the Canadian justice system so much more lenient than it is in the US?

I haven't really studied the Justice System of Canada but if it is similar to the British Laws then indeed it will be lenient. Their system doesn't believe in hanging and maximum of 25 to life in prison for murder although the majority of the time the prisoner is release before the 25 years is up. The majority of the time for some reason these prisons are executed by their own inmates before they finish their time. You live by the sword you die by the sword.