There was no error in overruling the certiorari.
(o) On a trial by a municipal court, the extent to which the credibility of witnesses, who admit that their obtaining a stipulated reward is dependent on conviction of the accused, may be affected by that fact is a matter left to the trial court. It may altogether disregard a witness thus interested, or may believe him. Ford v. State, 13 Ga. App. 68 (4), 69 (78 S. E. 782).
(6) An oral expression, on the part of the trial judge, of doubt as to the sufficiency of the proof of the defendant’s guilt, whether made prior to the signing of the judgment of guilty or thereafter, can not be used to impeach that judgment. See Jackson v. State, 15 Ga. App. 179 (2), 180 (82 S. E. 771), and cases cited. Judgment affirmed.