Deuteronomy Phist was the mayor of Central City during Green Lantern (Hal Jordan) and Green Arrow's trip across America. With funding from Lexcorp, Phist instituted a "War on Crime" program that took harsh measures to enforce the law and deal with criminals. Among its measures were heavier weapons for officers and more aggressive day-to-day policing (to the point of arresting drivers with unregistered plates). While the program produced remarkable results, it also allowed Phist to gain a distressing degree of control over the city.
Green Arrow, Green Lantern and the Flash joined forces to stop Phist's final stage, the illegal Project Rehab, and defeated the corrupted Central City police (along with their new operative, METACop). Phist's illegal actions and methods were exposed, and he was arrested (presumably losing the mayorship in the process).