The seeming contradiction over how Adam Lanza could have used a Bushmaster AR-15 rifle in the shootings when that same weapon was supposedly found locked in the trunk of his car afterwards was cleared up a few days later. The weapon found in the trunk of Lanza's car was a shotgun, not an AR-15:
Adam Lanza brought three weapons inside Sandy Hook Elementary school on December 14 and left a fourth in his car, police said. Those weapons were a Bushmaster AR-15 rifle and two handguns — a Glock 10 mm and a Sig Sauer 9 mm. In the car he left a shotgun ...