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. Angus wounded the Moderator before dying. The Doctor rescued the Moderator and took him to a hospital, ensuring that he got on life support. Dogbolter had his assistant Hob disconnect the Moderator from life support, killing him. (DWM: The Moderator)