Correlation does not mean causation, but this article has a nice figure or two and some numbers to show that, for some strange reason, states with gun control have less gun-related deaths. I would say heaps of the correlations here are spurious--that they are actually reflecting something else. That is, states that voted for McCain do not use guns to kill people because they are McCain voters, but rather the conditions that might lead to more McCain voters would also lead to more gun-related deaths. For instance, if a state's population really wants un-regulated guns, then they would vote for McCain and reap the benefits of un-regulated guns--more deaths.
Anyhow, check it out. Some inconvenient facts here, no doubt.