Richards portrayed a young Richard Webber in two Grey's Anatomy episodes: "The Time Warp" in season six, and "Only Mama Knows" in season eleven. He also appeared in an episode of The Mentalist. Richards had played the part of Damon in "Just Say Yes", a 1998 episode of the science fiction television series Sliders. Richards also guest-starred in an episode of Syfy's Warehouse 13.
Richards has so far been featured in four series as an attorney: Beginning in the first episode of season five of Angel, "Conviction," Gunn becomes a Lawyer after having his brain upgraded with a comprehensive knowledge of the law (both human and dæmonic) by the international and interdimensional law firm Wolfram & Hart. In 2006, Richards joined the cast of NBC's Law & Order spin-off Conviction as Billy Desmond, an undefeated New York City Assistant District Attorney with political aspirations. He has also been featured in CBS's CSI: Miami as the Floridian attorney Bob Villa, and portrayed attorney Marcus McGrath in the TNT series Raising the Bar until its cancellation.
Also in 2013, Richards created his own sci-fi web series called The Hypnotist.