Tearing Through (1925)

When District Attorney Johnson is seemingly unable to defeat a gang of drug smugglers, his assistant, Richard Jones, sets out on his own to investigate the lawbreakers. Richard soon learns that Bob Madison, the brother of the girl he loves, is a drug addict under the control of the gang. Bob joins the investigation, which leads them to an opium den in Chinatown owned by Mr. Greer, who is a rival for Bob's sister, Constance. Richard rescues her from one of Greer's drug dens, then discovers that the district attorney is taking bribes from the narcotics ring. As a reward for his outstanding work, Richard is appointed the new district attorney.