Paul gives a witness to the gospel. King Agrippa is persuaded strongly. Governor Festus believes that Paul is out of his mind from too much study - and so was not persuaded. (It resembles the same pattern where Jesus witnesses to two thieves on the crosses around Him, but only one of them chooses to follow Him. From all other accounts, the other didn't). In any event, the Festus and Agrippa are convinced Paul is not a criminal in any sense.