Case 108
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.
Riley
“Casey is innocent.”
Sam
“Riley is guilty.”
Kendall
“Neither Cameron nor Casey is guilty.”
Cameron
“Riley and Kendall are both innocent.”
Casey
“Kendall is innocent.”
Who is guilty?
Solution: Sam
If Sam is guilty, Sam's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.