Case 234
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.
Harper
“Marley and Kai are both innocent.”
Taylor
“Harper and Kai are both innocent.”
Marley
“Neither Taylor nor Kai is guilty.”
Emery
“Either Harper or Kai is guilty.”
Kai
“Either Taylor or Emery is guilty.”
Who is guilty?
Solution: Emery
If Emery is guilty, Emery's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.