The highest murder rate is in South Africa and Central America with Colombia having the honor of the highest murder rate. North America is relatively low on the list. Take a look.http://en.wikipedia.org/wiki/List_of_countries_by_murder_rate
I stand corrected, I thought the US has the highest murder rate. However, it doesn't diminish the connection between the number of guns in legal circulation and the number of murders commited in either the US or those other countries.
Is it possible to legally purchase a gun in the other countries you mentioned?