CASE ZERO
Case 335

Who is guilty?

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

Isla: “The guilty person is one of Isla, Freya or Cole.”
Sam: “Isla is innocent.”
Freya: “Neither Freya nor Cole is guilty.”
Cole: “The guilty person is one of Sam, Freya or Cole.”
Eva: “The guilty person is either Freya or Cole.”
Random case
Solution: Freya 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.