Ameren Illinois Co. operated a facility in downstate Galesburg. It hired Brian Knox in 1998 and promoted him to crew leader in 2015.Knox was represented by the International Brotherhood of Electrical Workers, Local 51.In June 2016, Knox engaged in a series of heated arguments with his supervisor, Gabriel Jones, pertaining to work schedules. Knox’s co-workers later told Jones that Knox owned multiple guns and regularly carried concealed weapons.Shortly afterward, Ameren officials, accompanied by a deputy sheriff …