Residents A, B and C, each of whom are either a Liar or a Knight are brought to stand trial for a crime only one of them commited.

Each person accused one of the other two, but the records do not show who exactly. As it turned out, A was the only Knight of the three.

Curiously enough, if each person switched their testimony, and accused the remaining suspect (not themselves, and not who they accused originally), then B would come out to be the only Knight.

Who was the real culprit in the case?