Case 261
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.
Casey
“Lane and Dakota are both innocent.”
Lane
“Either Elliot or Logan is guilty.”
Dakota
“Either Casey or Logan is guilty.”
Elliot
“Casey and Dakota are both innocent.”
Logan
“Elliot is guilty.”
Who is guilty?
Solution: Logan
If Logan is guilty, Logan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.