The angry chief of police did roar, "Who robbed the bank out of you four?" When Al was asked, he said right then, " The thief was Ben! The thief was Ben!" Ben said to the policin' man, "The thief was Dan! The thief was Dan!" When Carl was questioned, he exclaimed, "I'm not the one who should be blamed!" When Dan was questioned, he replied, "When Ben said it was me, he lied!"
If three of four suspects speak true, And one speaks false, then who oh who?
And what if only one was frank?
But most of all, who robbed the bank?