On 16 April 1986 Günther Tschanun opened fire in his workplace in Zurich, Switzerland, killing four people and seriously injuring one.

On 16 April 1986, Günther Tschanun opened fire in his workplace, the administrative building Amtshaus IV, with a Taurus Model .38 Special revolver, killing 4 and injuring 1.

[4] The department Tschanun worked at was experiencing difficulties and tensions in the workplace, and several days before the shooting an article that criticized his business management practices was published in the Züri-Woche [de].

Soon after this was published, two officials wrote a letter to their superior criticizing Tschanun and calling for his dismissal.

[1][4] Tschanun was initially sentenced to 17 years in prison in 1988 by the Zürcher Obergericht, for four counts of intentional homicide.The federal prosecutor wanted a verdict for murder, and took the case to the supreme court.

[3][7] Some people in the left wing in Switzerland at the time were accused of downplaying Tschanun's actions, viewing him as a "victim of the capitalist system" who had been under too much pressure.