Harry Sline

 was a criminal who was arrested for slave trading between Mars and Venus in the 22nd century. He and John Ladiver were being taken back to Earth for trial aboard the Starfinder. He tried to escape and was shot. Sline later betrayed Ladiver and the Starfinder crew to the Daleks so he wouldn't have to return to Earth. (AUDIO: The Curse of the Daleks)