This Bible contradiction is from the Skeptic's Annotated Bible.
Matthew 14:1-2 View context
At that time Herod the tetrarch heard of the fame of Jesus,
And said unto his servants, This is John the Baptist; he is risen from the dead; and therefore mighty works do shew forth themselves in him.
Mark 6:16 View context
But when Herod heard [thereof], he said, It is John, whom I beheaded: he is risen from the dead.
Luke 9:9 View context
And Herod said, John have I beheaded: but who is this, of whom I hear such things? And he desired to see him.