The president has a new plan, which he hopes will curb gun violence. He wants more background checks and a ban on assault weapons.
But exactly what is an assault weapon?
Only certain guns are called assault weapons, even though they're all designed to assault a target. So when our politicians push to ban "assault weapons," pay attention to how they define "assault."
In general, they say assault weapons are guns that can fire a lot of shots without reloading, and that fire each time you pull the trigger. But that does not include handguns.
Assault weapons, as defined by Congress, also look like military-style rifles. They have detachable magazines and typically shorter barrels.
But when Congress banned assault rifles in the 90's, gun-makers worked around it by making a number minor adjustments that no longer fit the official definition. So a ban will face challenges from those who question its effectiveness, as well as those who just don't want it.
The White House will also try to close the gun show loophole. You need to get a background check to buy a gun from a store, but you don't always need one to buy from a gun show.
For now, the rules in Florida vary from county to county and dealers require checks, but private sellers may not. So two people could go to the same gun show, buy the same type of gun, and have two different experiences.
The push in Washington would change that -- require background checks across the board.
But would any of these changes have prevented the Newtown massacre?
Universal background checks alone would not. The killer took weapons from his mother.
He did have a semi-automatic rifle, so a ban could have affected the weapons he used. But both sides agree a determined killer can and do find ways to work around the law.
Keep in mind, bans would only affect future purchases, not weapons people -- like his mother -- already owned.