CASE ZERO
Case 267

Who is guilty?

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

Ruby: “Jade is innocent.”
Theo: “Finn is innocent.”
Mila: “Jade is guilty.”
Finn: “The guilty person is one of Ruby, Theo or Mila.”
Jade: “Neither Theo nor Finn is guilty.”
Random case
Solution: Mila 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.