No, it’s not by me. It’s by Eugene Volokh at the Washington Post, and it’s outstanding. He begins:
There’s been much talk recently — including from President Obama — about there being a substantial correlation between state-level gun death rates and state gun laws. Now correlation obviously doesn’t equal causation; there may be lots of other factors that are the true causes of both of the things that are being measured. But if we do look for now at correlation, it seems to me that the key question should focus on state total homicide rates, or perhaps (for reasons I describe below) total intentional homicide plus accidental gun death rates. And it turns out that there is essentially zero correlation between these numbers and state gun laws.
Volokh doesn’t address suicides in his analysis, and gun control advocates will no doubt take issue with that omission, but his findings are telling nonetheless:
The correlation between the homicide rate and Brady score in all 51 jurisdictions is +.032 (on a scale of -1 to +1), which means that states with more gun restrictions on average have very slightly higher homicide rates, though the tendency is so small as to be essentially zero. (If you omit the fatal gun accident rates, then the correlation would be +.065, which would make the more gun-restricting states look slightly worse; but again, the correlation would be small enough to be essentially zero, given all the other possible sources of variation.) If we use the National Journal data (adding the columns for each state, counting 1 for each dark blue, which refers to broad restrictions, 0.5 for each light blue, which refers to medium restrictions, and 0 for each grey, which refers to no or light restrictions), the results are similar: +0.017 or +0.051 if one omits the fatal gun accident rates. You can also run the correlation yourself on my Excel spreadsheet.
As Volokh notes, figuring out the effects of any given government policy on homicide rates is “devilishly difficult.” Thus, simplistic statements about gun control should be automatically suspect. I’d encourage you to read his entire post. Few people know more about the gun-rights debate than Volokh, and few scholars are as honest and rigorous.