Albert, Barney, and Curtis were questioned about the murder of Dwight. Evidence at the scene of the
crime indicated a lawyer might have been implicated in Dwight's murder. Each suspect made two statements, as follows:
- Albert said he was not a lawyer and that he did not kill Dwight.
- Barney said he was a lawyer and he did not kill Dwight.
- Curtis said he was not a lawyer and a lawyer killed Dwight.
The police subsequently discovered that only two of the statements quoted above were true, and only
one of the three suspects was not a lawyer.
Which of the suspects killed Dwight?
1) Assume A is not a lawyer. Then B is a lawyer, so A1 and B1 are true, so all other statements are false. But A2 and B2 cannot both be false, so A is a lawyer.
2) Similarly, assume C is not a lawyer. Then B is a lawyer, so C1 and B1 are true, so all other statements are false. But A2 and B2 cannot both be false, so C is a lawyer.
3) Therefore, we know that B is the non-lawyer, and that A1, B1 and C1 are all false. So which two of A2, B2 and C2 are true? It cannot be A2 and B2, because that would make C the killer and that would make C2 true also. Therefore, either A2 or B2 is a lie told by the killer, and C2 must be true. C2 says that the killer is a lawyer, so the killer must be A (not B).
Final answer: Albert killed Dwight.