CASE ZERO
Case 299

Who is guilty?

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

Ruby: “The guilty person is one of Ruby, Theo or Mila.”
Theo: “None of Theo, Mila or Finn is guilty.”
Mila: “The guilty person is one of Theo, Mila or Finn.”
Finn: “Ruby is innocent.”
Jade: “Theo is guilty.”
Random case
Solution: Theo 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.