Frank Eugene Harper, known professionally as Hill Harper, is an American film, television and stage actor, and author. He is best known for his nine-season role as Dr. Sheldon Hawkes on the CBS police procedural television series “CSI: NY”. CBS announced that Harper will be joining the cast of Limitless. He will be playing the role of Special Agent Spelman Boyle. The show will air on CBS in the fall of 2015, with the pilot to air on Tuesday, September 22, 2015 at 10:00pm EST / 9:00pm CST.