Case 055
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.
Riley
“Noah is innocent.”
Noah
“Harper is innocent.”
Rowan
“Noah and Harper are both innocent.”
Drew
“Harper is guilty.”
Harper
“Neither Riley nor Noah is guilty.”
Who is guilty?
Solution: Drew
If Drew is guilty, Drew's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.