Adam Lanza, the late 20-year-old Sandy Hook shooter, who on December 14, 2012, stormed into the Sandy Hook Elementary School in Newtown, Connecticut, killing 26 (mostly kids) and self, executed his deadly rampage in less than five minutes — said the Connecticut prosecutor leading the investigation, according to KSBY.com.
State's Attorney Stephen J. Sedensky III says Lanza killed all the victims inside Sandy Hook Elementary School with a Bushmaster .223-caliber rifle before taking his own life with a Glock 10 mm handgun. He added that Lanza also had another loaded handgun with him inside the school — as well as three 30-round magazines for the Bushmaster (a loaded 12-gauge shotgun, containing 70 shotgun rounds, was also found in the passenger compartment of the car Lanza drove to the school).
According to NBC News, Lanza fired 155 bullets — 154 fired from a Bushmaster .223-model rifle and a final bullet, fired from the Glock 10mm handgun. In addition, three Samurai swords were recovered from the Newtown home that Lanza shared with his mother (also recovered were a National Rifle Association certificate, seven of Lanza's journals, drawings that he made and books, including an NRA guide to the basics of pistol shooting).
Among the other items seized were a holiday card containing a check from his mother to buy a firearm, and an article from The New York Times about a school shooting at Northern Illinois University.