At the close of the evidence or at such other time during the trial as the court reasonably directs, either party may file and, in such event, shall serve on the opposing party written requests that the court instruct the jury on the law as set forth in those requests. The court shall inform counsel of its proposed action upon the requests before counsel’s argument to the jury, but the court shall instruct the jury after the arguments are completed. However, in the sentencing phase of the trial of a capital case, the court may, in its discretion, instruct the jury at the beginning of the proceeding. If the trial court elects to do so, it shall not be required to instruct the jury again after the arguments are completed, but it may if the court believes the interest of justice so requires. The judge shall write on each request “given” or “refused,” as the case may be, and the request shall thereby become a part of the record. Each request marked “given” shall be read to the jury without reference as to which party filed the request. Neither a copy of the charges against the defendant nor the “given” written instructions shall go to the jury room; provided, however, that the court may, in its discretion, submit written charges to the jury. Every oral charge shall be recorded by the court reporter as it is delivered to the jury. The refusal of a requested written instruction, although a correct statement of the law, shall not be cause for reversal on appeal if it appears that the same rule of law was substantially and fairly given to the jury in the court’s oral charge or in other charges given at the request of the parties. In charging the jury, the judge shall not express his or her opinion on the evidence. Submission of additional explanatory instructions shall not be required unless requested by the court.