Case 227
The Missing File
A signed contract file vanished from the archive.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Jordan
“Either Quinn or Finley is guilty.”
Quinn
“Casey is guilty.”
Morgan
“Jordan and Finley are both innocent.”
Casey
“Jordan and Morgan are both innocent.”
Finley
“Neither Jordan nor Casey is guilty.”
Who is guilty?
Solution: Quinn
If Quinn is guilty, Quinn's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.