That's some pretty slippery slope there. I'm sure many people posted "I like it, thousands die in WTC crash, and your priority is hypothetical restrictions on your rights" shortly after 9/11, and look at where we are now...
EDIT: We're at 17 school shootings this year with 17 dead, 21 wounded. Are gun control advocates significantly closer, with dead children as their evidence and motivation, to getting rid of gun rights? In this circumstance it's two dead adults, granted in a very public place. Gun control advocates have all the ammunition, so to speak, to achieve their goals if they're ever going to achieve them this incident or another tomorrow is not going to change the equation.
That's his letter stating his decision.
Instead of outlawing gun control how about we outlaw crazy people from carrying them. Or better yet hold the parents of children responsible who go off and do shootings in schools. If they let their kid stockpile weapons in their basement then they should be responsible in some way for what their child does. (I am talking about Columbine type stuff, not the LAX shooting)