2006 Weston High School shooting

On September 29, 2006, a school shooting occurred at Weston High School in Cazenovia, Wisconsin. Eric Hainstock, a 15-year-old freshman, arrived at the school around 8:00 a.m. carrying a .22 caliber revolver and a 20-gauge shotgun that he had taken from his father's locked gun cabinet. He entered the school's main hallway and aimed the shotgun at a social studies teacher. School custodian Dave Thompson wrestled the shotgun away from Hainstock before Principal John Alfred Klang entered the hallway and confronted him.

Hainstock, still armed with the revolver concealed in his jacket, drew the weapon and fired several shots. Klang grabbed Hainstock, wrestled him to the ground, and swept the gun away, ending up on top of him as a pool of blood formed near Klang's leg. Staff and students then held Hainstock until police arrived. Klang was the only person shot during the incident. He was treated at Reedsburg Area Medical Center and underwent surgery before being flown to University of Wisconsin Hospital in Madison, where he died shortly after 3 p.m. For his actions in disarming and subduing Hainstock, Klang was posthumously awarded the Carnegie Medal by the Carnegie Hero Fund. In the aftermath, high school students were taken to the elementary school gym for optional counseling or dismissal, elementary students were sent home, and homecoming events were canceled.

Background reporting describes Hainstock's upbringing, including his parents' divorce, the termination of his mother's parental rights, and periods living with his father, stepmother, and paternal grandmother following a 2001 child-welfare referral. Hainstock later wrote to the Madison newspaper Isthmus alleging harsh treatment and household demands by his father, and stated he had been bullied by fellow students at Weston High School, claiming faculty did not intervene when he reported it. He told police after the shooting that he had not intended to hurt Klang and had wanted to confront him about the bullying. Reporting also notes he had been treated with medication for ADHD, and a psychologist retained by his public defenders later diagnosed him with ADHD, depression, and features of borderline personality disorder.

Hainstock was charged with first-degree murder by the Sauk County District Attorney's office. He was found guilty on August 2, 2007, and sentenced to life imprisonment, with parole eligibility in 2037. He has been incarcerated at Green Bay Correctional Institution and is currently held at Oshkosh Correctional Institution. While imprisoned, he shared his account with Isthmus and later authored a self-published cookbook released in 2019. His father, Shawn Hainstock, died on March 1, 2023, in La Valle, Wisconsin.