Case 042
The Disabled Camera
A security camera was deliberately switched off.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Hayden
“Emery is guilty.”
Emery
“Either Casey or Drew is guilty.”
Casey
“Drew and Harper are both innocent.”
Drew
“Hayden is innocent.”
Harper
“Hayden and Casey are both innocent.”
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.