Case 202
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.
Peyton
“Either Marley or Frankie is guilty.”
Morgan
“Peyton and Frankie are both innocent.”
Marley
“Frankie is guilty.”
Frankie
“Marley is guilty.”
Finley
“Neither Peyton nor Morgan is guilty.”
Who is guilty?
Solution: Marley
If Marley is guilty, Marley's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.