Case 331
The Lost Access Card
A master access card was taken from the reception desk.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Emery
“Neither Sam nor Dakota is guilty.”
Sam
“Either Emery or Rowan is guilty.”
Dakota
“Neither Emery nor Hayden is guilty.”
Rowan
“Emery is guilty.”
Hayden
“Neither Emery nor Sam is guilty.”
Who is guilty?
Solution: Rowan
If Rowan is guilty, Rowan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.