I'm not an expert on crime etc, but I want to say the following...
As a woman living in Europe, I HAVE been in a situation where a man (not a group of men) tried to rape me. I was at an age I should probably not mention, and the man was about 35. I won that fight. I did not have a gun (and I doubt that even in the US it would have been legal for me to carry one at that age). What made me win that fight, was the luck I'm not one of the women who freeze (it's something you cannot control) or panic, but I continued to be able to think; I also was more nimble than the guy, and I hit him hard in a sensitive spot (on his throat). I got free, and ran off.
I also have been attacked by a group of 3 boys in a public place, and again won that fight by kicking two of them where it hurts, and the third then let go of me. I later learned I should have attacked the one holding me first, but whatever, it worked and I got out. Also at that time, I was at an age that probably should not be mentioned.
In case I had had a gun and would have been able to fire it (not a good idea when someone is holding you from behind, as you can't see what you're firing at and would maybe shoot yourself in the foot), maybe escaping would have been easier / could have prevented being attacked in the first place in one instance. BUT...
Also, chances would have been higher that at least one of my attackers would have been armed as well, and they would have been more prepared. In that case, I may have been just too scared to even try fighting, leading to a totally different outcome...
Then another thing, not related to a situation of attack: how many accidents happen in the US each year with children playing with the guns found at home, with death or permanent injury of a sibbling or friend as the consequence? ALL of those accidents could have been prevented if guns were forbidden in the US.
Just my two cents...