(a) In any first degree murder case in which the state does not seek the death penalty, but is seeking imprisonment for life without possibility of parole as the maximum punishment, should the jury find the defendant guilty of first degree murder, the jury shall fix the punishment in a separate sentencing proceeding, to determine whether the defendant shall be sentenced to imprisonment for life without possibility of parole or imprisonment for life. The sentencing proceeding shall be conducted in accordance with § 39-13-204, excluding references to the death penalty.

(b) If the jury unanimously determines that no statutory aggravating circumstance or circumstances have been proven by the state beyond a reasonable doubt, as set forth in § 39-13-204(i), the jury shall return its verdict to the judge on the form described in § 39-13-204(f)(1), and the court shall sentence the defendant to imprisonment for life.

(c) If the jury unanimously determines that the state has proven beyond a reasonable doubt one (1) or more of the statutory aggravating circumstances set forth in § 39-13-204(i), the jury shall, in its considered discretion, sentence the defendant either to imprisonment for life without possibility of parole or to imprisonment for life.

(d) The jury shall be instructed that, in imposing sentence, it shall weigh and consider the statutory aggravating circumstance or circumstances proven by the state beyond a reasonable doubt and any mitigating circumstance or circumstances.

(e) The jury shall then return its verdict to the judge upon a form provided by the court, which may appear substantially as follows:

(f) If the jury cannot ultimately agree as to punishment, the judge shall dismiss the jury and the judge shall impose a sentence of imprisonment for life. The judge shall not instruct the jury, nor shall the attorneys be permitted to comment at any time to the jury, on the effect of the jury's failure to agree on a punishment.

(g) When a defendant has been sentenced to imprisonment for life without possibility of parole, the defendant may appeal the sentence to the Tennessee court of criminal appeals. The court of criminal appeals shall first consider any errors assigned and then the court shall review the appropriateness of the sentence. A sentence of imprisonment for life without possibility of parole shall be considered appropriate if the state proved beyond a reasonable doubt at least one (1) statutory aggravating circumstance contained in § 39-13-204(i), and the sentence was not otherwise imposed arbitrarily, so as to constitute a gross abuse of the jury's discretion.