Art. 770. Prejudicial remarks; basis of mistrial

           Upon motion of a defendant, a mistrial shall be ordered when a remark or comment, made within the hearing of the jury by the judge, district attorney, or a court official, during the trial or in argument, refers directly or indirectly to:

           (1) Race, religion, color or national origin, if the remark or comment is not material and relevant and might create prejudice against the defendant in the mind of the jury;

           (2) Another crime committed or alleged to have been committed by the defendant as to which evidence is not admissible;

           (3) The failure of the defendant to testify in his own defense; or

           (4) The refusal of the judge to direct a verdict.

           An admonition to the jury to disregard the remark or comment shall not be sufficient to prevent a mistrial. If the defendant, however, requests that only an admonition be given, the court shall admonish the jury to disregard the remark or comment but shall not declare a mistrial.