Information from CNN's site, including information from the medical examiner:
Lanza was found dead next to three guns, a semi-automatic .223-caliber Bushmaster rifle and two pistols made by Glock and Sig Sauer, a law enforcement source told CNN. All belonged to his mother.
Carver, who performed autopsies on seven of the victims, said the wounds he knew about were caused by a "long weapon." Asked by a reporter whether the rifle was the primary weapon, he responded, "Yes."
http://www.cnn.com/2012/12/15/us/con...html?hpt=hp_t1