Case 283
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.
Sam
“Neither Morgan nor Frankie is guilty.”
Quinn
“Dakota is guilty.”
Morgan
“Neither Sam nor Frankie is guilty.”
Dakota
“Quinn is guilty.”
Frankie
“Sam and Quinn are both innocent.”
Who is guilty?
Solution: Dakota
If Dakota is guilty, Dakota's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.