The rifle he used, a .223-caliber Bushmaster M4 carbine, was legal under Connecticut's "assault weapon" ban, which is similar to the federal law that expired in 2004
You know what everyone, what we need is an assault rifle ban. An assault rifle is some sort of mysterious weapon forged in the fires of hell solely for the purpose of murdering people. No one knows exactly what it is, but if we just bring back the Assault Weapons ban, it will have absolutely no impact as, not only did Connecticut have an Assault Weapons ban, but the ban does not cover the rifle Lanza used.
The rifle he used, a .223-caliber Bushmaster M4 carbine, was legal under Connecticut's "assault weapon" ban, which is similar to the federal law that expired in 2004. Both laws, in addition to listing specifically prohibited models, cover semiautomatic rifles that accept detachable magazines and have at least two out of five features: 1) a folding or telescoping stock, 2) a pistol grip, 3) a bayonet mount, 4) a grenade launcher, and 5) a flash suppressor or threaded barrel designed to accommodate a flash suppressor. The configuration of the rifle used by Lanza, which his mother legally purchased and possessed in Connecticut, evidently was not covered by that definition.
Most of those features have very little to do with the assumptions that most 2nd Amendment opponents have about assault rifles.