Okay, the shooter of the fireman did not shoot his grandmother, he beat her to death with a hammer. And so far, I've not seen that the police have released any info about the gun used, how/where it was bought, by whom, etc. This guy was a convicted felon, and by laws already in existence, is prohibited from buying/owning any guns. So yeah, pass another gun law, I'm sure he would've observed *that* one, per your line of thinking, right?
Why do you feel the need to simply make stuff up? You apparently feel that your case isn't strong enough on its own merits?