RP n°3 : A mystery to solve

A man is found dead one Sunday morning in his London house.  He was killed while his wife was sleeping. The wife tells the police all that she knows. She tells them that the cook was preparing breakfast in the kitchen. He was buttering some slices of toast. The maid was cleaning the living room, as she always does at week-ends. The butler was outside with the family dog. He was getting the mail.

  1. Who are the 4 suspects? What were they doing at the time of the crime?
  2. The police immediately arrested the murderer. Who is the murderer and why?