Hmm... haven't thought much about it. I don't know that it makes sense in every situation. If a parent supplied a gun or was negligent about making sure their kid didn't get hold of one, I do think criminal charges might make sense. But I'm also mindful of the fact that our criminal justice system seems to use only a couple of tools -- turning more things into crimes and increasing the sentences for existing crimes -- and those tools often don't seem to work all that well to deter bad behavior.