Keith did it first (2003 - 2004 - 11 episodes), and David did it second (2004 - 2005 - 22 episodes). I saw one episode that they were both in.
Ah, yes, the transitional one. In retrospect, Keith was growing his handlebar to star in Deadwood as Wild Bill Hickock.
News reports are now softening the suicide angle. And Bangkok being what it is, there are numerous other likely possibilities, including an accident. Let's wait and see.