CASE ZERO
Case 359

Who is guilty?

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

Isla: “None of Isla, Freya or Eva is guilty.”
Sam: “Neither Sam nor Eva is guilty.”
Freya: “The guilty person is one of Isla, Sam or Cole.”
Cole: “Neither Isla nor Freya is guilty.”
Eva: “None of Isla, Cole or Eva is guilty.”
Random case
Solution: Sam 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.