The Purple Vigilantes

The Purple Vigilantes is a 1938 American Western film directed by George Sherman and starring Robert Livingston, Ray Corrigan, and Max Terhune. Written by Betty Burbridge and Oliver Drake, the film is about a rancher who organizes other ranchers to form a vigilante group in order to rid their town of outlaws. After the outlaws are defeated, some of the men, posing as the vigilant group, go on a crime spree. The Purple Vigilantes is the 12th entry in the Three Mesquiteers series of Bmovies produced by Republic Pictures. The film was released in the United Kingdom as Purple Riders.

Source: Wikipedia