Where counsel in the hearing of the jury make statements of prejudicial matters which are not in evidence, it is the duty of the court to interpose and prevent the same. On objection made, the court shall also rebuke the counsel and by all needful and proper instructions to the jury endeavor to remove the improper impression from their minds; or, in his discretion, he may order a mistrial if the prosecuting attorney is the offender.
OCGA § 17-8-75