If I may, the murder rate is directly related to the drug trade. The drug trade here is linked to the mainland drug trade. Demand is the problem. As long as demand for drugs exist both here and on the mainland, suppliers will find a way to get it into the country, and kill for their turf in the trade. The only way to reduce demand is through education and strong families and faith, in no particular order.
In my libertarian moments (and I have those every once in a while), I do wonder what whether legalization would help (in net). It appears to me that the cure for our drug problems (more intrusive law enforcement) is worse than the disease. If you take organized crime out of the picture by legalization then prices fall as does the need for crime to pay inflated prices (and there is no need for turf wars either). Yes some people will be hurt by legalization - but mainly the hurt will be born by those who make bad choices, not by those who just happen to be in the wrong place at the wrong time. And yes, it should still be illegal to endanger others through your behavior (as in driving while high or drunk). My 2 cents.