Case 329
The Vanished Key
A locked evidence cabinet was opened without permission.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Harper
“Logan and Jordan are both innocent.”
Elliot
“Jordan is innocent.”
Logan
“Harper and Elliot are both innocent.”
Jordan
“Neither Harper nor Logan is guilty.”
Dakota
“Either Logan or Jordan is guilty.”
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.