"The assault rifle has become the weapon of choice in drive-by shootings."
I doubt that's true, based on what I've seen, but I'm willing to look at your sources. To my knowledge, the only place you see someone trying to shoot rifles out of the seat of a moving car is a video game.
You're playing catch-up on the data, and as usual, trying to do it without actually using any data.
Politicians are using this incident to enhance their political position with voters, as they often do with tragedies and disasters. They don't have to actually solve a problem, they just have to get the voters to think they will.