The butler's life partner (the blonde avocado, not the flounder) did it with a frozen waffle in Miss Marple's rumpus room. The purple faux fur found in Lord Hamperdamp's nasal cavities was a red herring of another color. He was a closet Muppet sniffer (weekends and rainy afternoons). How his trousers, left shoe and a signed copy of "Rear Window" got in there is another story. (Copies available in the lobby).
The cat was not involved in the murder, but was found guilty of loitering in a story with the intent to attract cat fanciers and subsequently shot.
