After leaving the secretariat, Steinhäuser went up the stairs to the first floor. Still on the stairs, he shot several times in the back of a teacher who was about to open a preparation room. On the first floor, he moved into the room 105 and shot the teacher in front of the students. Alerted by the shots, the teacher from the opposite classroom wanted to see what had happened and entered the corridor, where he was killed by several shots.