A boy that had been expelled from the school 2 months earlier, 19-year-old Robert Steinhäuser, was the person who did all the shooting. In anger, he came into the gymnasium, and shot dead 12 teachers, a secretary, two students, and a police officer. After a teacher caught him and put him in an empty room, Steinhäuser shot himself dead. In total, 17 people were killed.
According to students, he ignored them and aimed only for the teachers and administrators, although two students were unintentionally killed by shots fired through a locked door.
- "How a school shooting 15 years ago changed Germany". The Local Germany. 2017-04-26. Retrieved 2021-07-13.
- "Killer's secret behind revenge attack". the Guardian. 2002-04-29. Retrieved 2021-07-13.