I live a few blocks from the movies that were shot up the other night. In fact, I was up at when it happened and heard the sirens from all directions. After that, couldn't sleep. This really hits close to home quite literally as this was the movie theater I would frequent (low prices & really close by).
With that caveat, my opinions:
Let's ramp up the control as soon as we start winning that war on drugs 
In all seriousness though, I can't advocate eliminating the purchasing of pretty much anything he bought including the assault rifle and the 100 round clip. The purpose for the 2nd Amnd wasn't to have weapons for self-defense, the purpose was for the populace to be a threat (but I don't want to debate this really, so don't latch onto this one comment and derail) - really this is the only "questionable" weaponry he purchased IMO.
The most dangerous weapons were the ones in his apartment. If he wanted, he could have just tossed several home-made grenades into the seats and would have killed and maimed scores more than he did.
If someone in the theater was armed, perhaps that person could have slowed the attack.
Not to be results oriented
Free high quality education with a strong focus on science, medical care and a good welfare system is the best strategy against crime.
the shooter was a Phd student in neuroscience at the university hospital; came from what appears to be a fine middle class upbringing, and even won a scholarship/federal grant to study (but perhaps not enough to make it "free"... if anything, his education made him MORE dangerous.
But generally I agree, education will help reduce crime in general.
Start by reducing the budget of the military by 50%
I think the USA can cut back by over 75%, but banish the thought as such a proposal would be political suicide. Not to worry though, give it about 5-10 more years and the cut backs will be mandatory (IMO)