Nancy Pelosi will bring student from Newtown to Obama's State of the Union, but what would the proposed rules have done to stop that attack?

Newtown continues to be used as a prop for more gun control, but what proposal being put forward by Democrats would have prevent the attack if it had been in effect?  Can anyone explain to me which proposed regulation would have stopped the attack?  Yet, Nancy Pelosi will bring student from Newtown as a prop for Obama's State of the Union.

"Universal background checks" -- The killer didn't buy the gun.  BTW, would this rule have stopped any of the attacks this last year?  No.  Of course, even if one of these killers would have been prohibited from buying a gun, that is not the same thing as saying that they would have not gotten a gun.  When people have 4 months of planning and have the time to put together dozens of bombs they don't even acknowledge how difficult it can be to stop such a person from getting weapons.  As Jamie Fox at Northeastern University correctly writes: "Most mass murderers do not have criminal records or a history of psychiatric hospitalization. They would not be disqualified from purchasing their weapons legally. Certainly, people cannot be denied their Second Amendment rights just because they look strange or act in an odd manner. Besides, mass killers could always find an alternative way of securing the needed weaponry, even if they had to steal from family members or friends."

Assault weapon ban -- The gun used in the Newtown attack wasn't even banned under the Connecticut Assault Weapon Ban.  It wouldn't have been banned under the feature set that would ban guns under the Feinstein bill.  New sales of the Bushmaster would have been banned by name under the Feinstein bill.  Of course, banning guns by name and not objective features shows how arbitrary the law is.

Magazine size -- Even if you somehow believe that magazine size would have altered the rate of fire in the Newtown attack, the key point there is that it took 10 minutes between when the first 911 call was made and first responders showed up outside the school.  

UPDATE: Here are a couple other relevant facts on these points.  From the Hartford Courant:

"It's just weird [that he popped in earplugs] given what he was about to go do," a source said. "It's not like he had to worry about long-term protection of his hearing because he had to know he wasn't coming back out of the building." 

As police wrap up at least the crime-scene portion of their investigation into Lanza's murderous spree that left 26 people dead in the school, including 20 first-graders, the earplugs are not the only evidence that shows Lanza might have carried habits either from the shooting range or the virtual world of video games into his real-world massacre. 

Lanza changed magazines frequently as he fired his way through the first-grade classrooms of Lauren Rousseau and Victoria Soto, sometimes shooting as few as 15 shots from a 30-round magazine, sources said. . . .