You were a ghost investigating your own murder, however other players have now completely destroyed all the evidence you needed to be able to win. On discovering you were a ghost, you would have gained a new goal. As your win condition was rendered impossible, the ghost hunter was able to finish you off quickly.
Thanks so much for filling in. I was in a jam when you came in, and it was made harder by players finding and hiding everything you needed to progress - sometimes without knowing thats what they were doing.