Thurston High School (1998 shooting, Kip Kinkel)

On May 20, 1998, 15-year-old student Kip Kinkel was expelled from Thurston High School for bringing a firearm into school. After returning to his home from the police station, he got his father's Ruger semi-automatic rifle, then shot and killed his parents. The next day, on May 21, Kinkel drove his mother's car to the school, and, wearing a long trench coat, he entered the cafeteria and began shooting at students with the rifle. As he was reloading his rifle, Kinkel was subdued by seven other students who held him until the police arrived at the scene. The arresting officer was shocked that it was "just a kid" but his shock soon wore off upon searching the suspects' trench coat, which was full of knives, cartridges, and gun magazines. Two students were killed and 22 others were wounded. He was charged with four counts of aggravated murder. He later pleaded guilty and was sentenced to 111 years in prison. His case has become one of the standard case studies in profiling students who bring guns to school for purposes of murder, a prelude to the Columbine High School massacre.