Friedrich Leibacher (July 21, 1944 – September 27, 2001) was a Swiss spree killer who killed 14 members of the Zug canton Parliament, injuring 15 others, before committing suicide. July 21 is the 202nd day (203rd in leap years) of the year in the Gregorian Calendar, with 163 days remaining. ... Year 1944 (MCMXLIV) was a leap year starting on Saturday. ... September 27 is the 270th day of the year (271st in leap years) in the Gregorian calendar. ... 2001 (MMI) was a common year starting on Monday of the Gregorian calendar. ... A spree killer is someone who embarks on a murderous rampage. ... Zug (French: Zoug, Italian: Zugo) is one of the 26 cantons of Switzerland. ...

Leibacher had been employed in business, and had several failed marriages to women from the Dominican Republic, one of which produced a daughter. In 1970 he was convicted of fraud, public obscenity and obscene acts with children, and sentenced to 18 months detention. He served his sentence in a work-training institution.

After leaving detention, Leibacher became unemployed. Doctors diagnosed a personality disorder and alcoholism and he received an invalidity pension. In 1998 he was convicted of threatening a bus driver employed by the Zug transport company. Leibacher was upset by his treatment, and wrote frequently to the authorities with letters of complaint. The passage of time did not diminish his grievance as Leibacher began to believe he was the target of a government conspiracy led by Robert Bisig, a Cantonal Minister. He sued Bisig but in September 2001 his actions were dismissed by the court. Alcoholism is the consumption of, or preoccupation with, alcoholic beverages to the extent that this behavior interferes with the drinkers normal personal, family, social, or work life, and may lead to physical or mental harm. ...

At 10:30 AM on September 27, 2001 Leibacher entered the Zug Parliament disguised as a police officer and armed with a pistol, a pump-action shotgun, and a rifle. He made his way to the Parliament chamber where he fired more than 90 shots randomly. Politicians and journalists alike were hit, although Robert Bisig escaped unscathed. Finally, Leibacher detonated a small home-made bomb, then shot himself. He left behind a suicide note describing his action as a "Day of rage for the Zug mafia".