No, I haven't found a source of useful data. Guns are also legal here, as I've said previously, although very few can carry them legally in public. I suppose there's a temptation to carry licenced guns illegally in public. I believe that Thai nationals can by hand guns, shot guns and certain rifles but not military style gear. The odd thing is that I see few signs that
gun violence, the topic under discussion rather than homicide in general, is anywhere near as bad as some paint it as being in the US. An exception might be Phuket which seems to have become something like the Wild west recently but that's sinkhole for sleazy tourists. Even then, I don't think that guns are the most common weapon.
I don't support the Thai gun laws. There's no need for guns here, even for hunting. A better comparison with the US might be gun crime statistics for the UK since hand guns were banned. This is the reason why there was a public outcry in the UK demanding the banning of handguns:
http://en.wikipedia.org/wiki/Dunblane_school_massacre
You might find that the circumstances are similar to incidents where you live but the public and government response was, I'm glad to say, rather different.