Report: Shooter Had Run-In With School Staff Day Before NBC says Adam Lanza had altercation prior to massacre By John Johnson, Newser Staff Posted Dec 15, 2012 12:07 PM CST 109 comments Comments White balloons decorate a sign for the Sandy Hook Elementary School Saturday morning. (AP Photo/Mary Altaffer) (Newser) – NBC News adds one more piece to the puzzle: It reports that Adam Lanza had some kind of altercation with four staffers at Sandy Hook Elementary School on Thursday, the day before the massacre. Three of those staffers were killed, and the fourth was not at school yesterday and is being interviewed by police. It's not known what the dispute was about. NBC also says Lanza tried to buy a rifle at a sporting goods store but was unable to do so because of the state's waiting period. He was still well-armed when he arrived at the school, however, apparently with weapons registered to his mother, reports ABC News.