Case 174
The Empty Safe
A small office safe was found empty in the morning.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Riley
“Neither Quinn nor Parker is guilty.”
Quinn
“Parker is innocent.”
Kendall
“Either Quinn or Harper is guilty.”
Parker
“Neither Riley nor Harper is guilty.”
Harper
“Either Quinn or Kendall is guilty.”
Who is guilty?
Solution: Kendall
If Kendall is guilty, Kendall's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.