You know, murder also correlates to population. The higher the population, the more murders you have, so to minimize murders, you just have to minimize the population. Eureka! The solution to murder is zero population, or as you might say in pseudo mathematics, murders ends as population approaches zero.
And the number of guns becomes irrelevant.
This also takes care of many other social ills, such as poverty, hunger, war, etc.
And Ricky, the death penalty does have, at least, a minor deterrent. The person put to death is deterred from further murders.