You talk about Texas, where everything is spread out and compare it to a state like NJ where we have dense population.
I could point you to Japan, where guns are illegal and gun crimes are way below.
I can show you that as gun sales increase, gun crime increase in the US.
http://www.justfacts.com/guncontrol.asp
The graphs that show Florida, Texas, and Michigan show decrease, but the country as a whole also saw decrease in murder rates.