Jonny Lee Miller Sherlock Holmes Actor Lucy Liu Dr. Joan Watson Actor Aidan Quinn Capt. Tobias "Toby" Gregson Actor Jon Michael Hill Detective Marcus Bell Actor Michael Countryman Barry Kemper Guest Star Erin Dilly Amanda Kemper Guest Star Andrew M. Chamberlain 12-Year-Old Adam Kemper Guest Star Johnny Simmons Adam Kemper Guest Star Christopher Evan Welch Samuel Abbott Guest Star Yancey Arias Robert Castillo Guest Star Selenis Leyva Sara Castillo Guest Star Don Guillory News Cameraman Guest Star Larisa Polonsky Lori Thomas Guest Star Brian O'Neill Kemper Family Attorney Guest Star Flint Beverage Esu Sgt. O'Donnell Guest Star Robert Doherty Executive Producer Sarah Timberman Executive Producer Carl Beverly Executive Producer Michael Cuesta Executive Producer Peter Blake Writer Rod Holcomb Director