Case 013
The Lost Access Card
A master access card was taken from the reception desk.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Frankie
“Neither Jules nor Avery is guilty.”
Jules
“Avery and Reese are both innocent.”
Avery
“Jules and Reese are both innocent.”
Reese
“Neither Frankie nor Jules is guilty.”
Logan
“Jules is guilty.”
Who is guilty?
Solution: Logan
If Logan is guilty, Logan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.