In May 1917, a riot broke out in St. Louis; white ethnic workers, out on strike, attacked black strikebreakers, brought in to replace them. In July, mob violence broke out in East St. Louis against blacks, also against a background of competition over jobs. Two white police officers were killed early in the confrontation. In retaliation, white mobs killed 35 blacks, mutilated the bodies, and threw them into the Mississippi River. White rioters openly targeted and lynched several blacks. Those who attempted to stop the lynchings were threatened by the white mob with physical violence. As blacks fled into St. Louis, white rioters threatened to kill them upon their return. White Illinois National Guardmen, sent to quell the riot either did nothing to stop the violence or participated in the attacks on the black community instead. One black child was shot and thrown into a burning building, while white prostitutes openly attacked black women. After the riots, of the 134 persons indicted, only nine whites who were put on trial went to prison while 12 indicted blacks who went to trial were imprisoned. Nearly one-third of the total 134 persons indicted were black. The conviction rate, mathematically, was more than doubled for blacks than for whites.