You can include the police in "good guys", but that invalidates the phrase's relevance to citizens' rights to bear arms. Pick one or the other, but not both.
I suppose they are, if they're police, military or armed guards (although the latter are nearly absent in the stats of how shootings are stopped).
P.S. I'm not actually advocating gun control. It works fine, but only in a society with little private gun ownership to begin with. The US is going to have to live, and comparatively often die, with it.