Richardson became an Assistant District Attorney in the Bexar County district attorney's office in 1988, and in 1998 became an Assistant U.S. Attorney for the Western District of Texas in San Antonio. In 1999, Governor George W. Bush appointed Richardson to a seat on the 379th District Court. He remained on that office until 2008, when he lost a bid for reelection to Democrat, Ron Rangel.[2] In 2014, Richardson presided as a special judge on call over the 2014 indictment of Governor Rick Perry for alleged abuse of office. During the course of the proceedings, Richardson was elected to the Court of Criminal Appeals,[3][4] and thereafter denied the motion to dismiss the case against the governor.[5] Richardson won reelection in 2020.