The Moderator

The Moderator was a "troubleshooter" employed by Josiah W. Dogbolter to locate the Doctor's TARDIS for him. He tracked it to Earth, where he fatally shot the Doctor's companion Angus Goodman, who wounded the Moderator before dying. The Doctor rescued the Moderator and took him to a hospital, ensuring that he got on life support. Dogbolter, however, ensured that his assistant Hob disconnected the Moderator from life support, killing him. (DWM: The Moderator)