On Monday evening, October 21, 1872, a young man about 18 years old boarded the night express of the Atlantic and Pacific Railroad at Springfield. When the conductor, identified only as B. Percy, passed through the passenger car collecting fares, the young man had no ticket and no money to pay for one but said he would be able to obtain some money at Marshfield. The conductor allowed the lad to ride to Marshfield, but when the train arrived there, the young man still showed no disposition to pay. The conductor then took the young man's hat and left it with the ticket agent, telling the lad he could get the hat back when he came up with the money for his ticket. A few moments later, Conductor Percy announced "all aboard" and stepped onto the platform of one of the rear cars as the train started up. The young man scaled the platform from the opposite direction, immediately pulled out a pistol, and shot the conductor through the head. The desperado then jumped from the train and disappeared into the darkness. Because of the noise created by the train starting up, the shooting was not discovered until the train had traveled from the passenger depot to the freight depot about a hundred yards distant. The confusion and excitement caused by the discovery further aided in the shooter's escape. Percy died within twenty minutes, and the next morning his body was taken to Springfield, where he had lived, and turned over to his family.
Although the murderer fled into the night without being immediately pursued, a posse soon started after him and trailed him to a residence about seven miles east of Springfield, where he had stopped and been allowed to rest. The posse found the young man sound asleep inside the home about midday on Tuesday, tied him with a rope, and started back to Marshfield with their prisoner, who identified himself as V.T. Cornwell of Illinois. The editor of the Springfield Missouri Weekly Patriot
expressed satisfaction that the man who had killed Percy was taken back to Marshfield rather than brought to Springfield because "our people are slow to punish such heinous crimes" whereas "the people of Webster have had some experience in this line." The newspaperman said he looked to Webster County to give Cornwell justice and that he thought it could best be dispensed at the end of a rope. What ultimately happened to the young killer, however, is not known.