28/10/20022002Tucson, Arizona, United StatesArizona40Robert Flores, a distraught nursing student who was failing academically, shot and killed three of his professors before turning the gun on himself. The gunman had threatened his school in the past. The four deaths at the University of Arizona sent shock waves through the community."Student Kills three profs, self". Arizona Daily Wildcat. October 29, 2002. Retrieved December 24, 2013. |Holguin, Jaime (October 30, 2002). "Arizona Gunman had threatened School". CBS News. Retrieved December 24, 2013.