Check out this link to "Gun Myths";
http://www.duke.edu/~gnsmith/articles/myths.htm. Felons interviewed stated that they feared the armed citizen more than the police. No valid unbiased study shows that a citizen using a firearm for selfprotection is more apt to by hurt by the firearm than the assailant.
Ok, I misstated a stat that I had only partly memorized. There are about 2 million incarcerated felons in the US right now. But, there are about 6.9 million that are under control of the Prison Systems, i.e. parolees, probationioners, house arrests and a few other minor categories. A very scary figure if one takes into consideration that those are only the ones that got caught and prosecuted.
Also, check out a study by Dr. Gary Kleck on statistical analysis of firearm uses in the US. He started out as a confirmed anti-gunner, but did the analysis strickly on the level with no agenda creep and became an avid proponet of personal firearm ownership being convinced by his own statistics.