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.
- "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.