Case 223
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.
Lane
“Neither Peyton nor Dakota is guilty.”
Peyton
“Dakota and Elliot are both innocent.”
Dakota
“Peyton and Elliot are both innocent.”
Elliot
“Either Peyton or Harper is guilty.”
Harper
“Either Dakota or Elliot is guilty.”
Who is guilty?
Solution: Harper
If Harper is guilty, Harper's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.