On April 9, 1891, Walker was involved in an altercation outside a saloon with a group of four white men exchanging racial insults. Members of the group, including bricklayer Patrick "Curly" Murray, approached Walker and reportedly threw a stone at his head, dazing him. Walker responded by fatally stabbing Murray with a pocket knife. A compliant Walker surrendered to police, claiming self-defense, but was charged with second-degree murder (lowered from first-degree murder). On June 3, 1891, Walker was found not guilty by an all-white jury, much to the delight of spectators in the courthouse. He returned to Steubenville to, again, work for the postal service, handling letters for the Cleveland and Pittsburgh Railroad.