 As a junior at Peoria Central Richardson was selected to first-team All-State by the Champaign-Urbana News-Gazette and second-team All-State by the AP and Chicago Sun-Times.In his senior year at Findlay College Prep, Richardson, along with Texas recruit Avery Bradley, led the Findlay College Prep Pilots to a high school national championship after beating Oak Hill 74-66 and finishing their season 33-0.Richardson joined fellow 2009 recruits, including Brandon Paul, on the University of Illinois 2009–10 men's basketball team coached by Bruce Weber.