If the police officer to whom the venire is delivered fails to return the venire as required, or if the jury fails to agree and is discharged by the municipal court, a new jury shall be selected and summoned in the same manner and the proceedings shall be continued as prescribed in section 12 to 17 of this chapter, unless the accused consents to be tried by the court. If the accused consents to a trial by the court, the municipal court shall proceed to the trial of the issue as if a jury had not been demanded.