The shooter in CT used an assault rifle for all the deaths. Each victim was shot multiple times.
No. He used a Glock and a Sig Sauer both handguns. The rifle was found in the car. He broke into the school by smashing the glass on the front door which was locked as were all other doors. Visitors were normally buzzed in by someone in the front office inside the front door. It was there that he took out his first victims who worked there. Someone apparently in the front office tried to make an announcement over the PA system but they were shot and killed. The mic remained open so the whole school heard the gun shots. Certainly ample warning and enough time, if there were armed security to take action.