Mark Thomas Valley is an American actor. He is known for his roles as Brad Chase in the TV drama Boston Legal, Oliver Richard in the NBC drama Harry's Law, FBI Special Agent John Scott in the Fox sci fi series Fringe, Christopher Chance in Fox's action drama Human Target, and Tommy Sullivan in ABC's Body of Proof.

The Human Target is the name of two fictional characters in American comic books published by DC Comics. The first is Fred Venable, while the second is private investigator and bodyguard Christopher Chance who assumes the identities of clients targeted by assassins and other dangerous criminals. The character has appeared in numerous books published throughout the decades and has appeared in television adaptations.