Case 016
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.
Parker
“Hayden and Noah are both innocent.”
Marley
“Neither Hayden nor Noah is guilty.”
Hayden
“Parker and Marley are both innocent.”
Reese
“Either Parker or Noah is guilty.”
Noah
“Parker and Hayden are both innocent.”
Who is guilty?
Solution: Reese
If Reese is guilty, Reese's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.