Case 192
The Broken Seal
A tamper seal on a storage crate was cut overnight.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Morgan
“Either Elliot or Marley is guilty.”
Kendall
“Marley is innocent.”
Elliot
“Kendall is innocent.”
Avery
“Kendall and Elliot are both innocent.”
Marley
“Avery is innocent.”
Who is guilty?
Solution: Morgan
If Morgan is guilty, Morgan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.