Ban high-capacity magazines?

[muon2]

Shouldn't the decision be based on the effectiveness of the law? If I look at data from two years ago, six states (and DC) had bans. If one compares those states to the per capita rate of gun homicides from 2011, those states are spread throughout the rankings with 4 states above and 2 states below the national average. Without any correlation in the data it suggests that a high-capacity magazine ban is not a particularly effective law.