CASE ZERO
Case 155

Who is guilty?

Exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.

Ruby: “None of Ruby, Theo or Finn is guilty.”
Theo: “Mila is innocent.”
Mila: “The guilty person is either Ruby or Jade.”
Finn: “None of Theo, Mila or Jade is guilty.”
Jade: “Neither Theo nor Jade is guilty.”
Random case
Solution: Ruby is guilty. Testing each possible culprit leaves this as the only assignment where the culprit's statement is false and all four innocent statements are true.