I wasn't saying it mattered if the gun used was legally or illegally obtained as far as the damage done - the victims end up just as injured/dead either way, you're right on that.
But because two people used illegally obtained gun(s) to commit illegal acts (last I checked, shooting people was illegal), some people will now want to take all legally-obtained guns from all law-abiding citizens (except the ones with the shiny bit of tin on their shirts, of course because we know they're infallible).
Kind of like if someone steals a car and kills someone with it, all legally-owned cars should be eliminated. Or, if you don't like the car analogy, how about if someone breaks into a pharmacy and steals some Oxycontin, and subsequently someone ODs on it. Should no one be allowed to have Oxycontin as a result of one person's crime?
Doesn't make a lot of sense to me.