Case 187
The Stolen Prototype
A prototype vanished from a secured workroom.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Parker
“Either Morgan or Reese is guilty.”
Morgan
“Casey is guilty.”
Casey
“Reese is innocent.”
Frankie
“Neither Parker nor Casey is guilty.”
Reese
“Either Parker or Morgan is guilty.”
Who is guilty?
Solution: Morgan
If Morgan is guilty, Morgan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.