Case 126
The Stolen Watch
A valuable watch disappeared during a private gathering.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Finley
“Either Marley or Emery is guilty.”
Taylor
“Marley is guilty.”
Marley
“Either Taylor or Emery is guilty.”
Blake
“Finley and Emery are both innocent.”
Emery
“Neither Finley nor Taylor is guilty.”
Who is guilty?
Solution: Marley
If Marley is guilty, Marley's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.