Case 021
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.
Rowan
“Neither Marley nor Cameron is guilty.”
Avery
“Cameron is innocent.”
Finley
“Either Avery or Marley is guilty.”
Marley
“Neither Avery nor Cameron is guilty.”
Cameron
“Rowan is innocent.”
Who is guilty?
Solution: Finley
If Finley is guilty, Finley's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.