Massachusetts General Laws Part IV. Crimes, Punishments and Proceedings in Criminal Cases (Ch. 263-280) Ch. 279, § 71

In addition to review of the entire case pursuant to section thirty-three E of chapter two hundred and seventy-eight, the supreme judicial court shall review the sentence of death imposed pursuant to sections sixty-eight, sixty-nine and seventy of chapter two hundred and seventy-nine. If the supreme judicial court determines that (1) the sentence of death was imposed under the influence of passion, prejudice or any other arbitrary factor or (2) the evidence does not support the jury's finding of a statutory aggravating circumstance or statutory aggravating circumstances as defined in section sixty-nine or (3) the evidence does not support the jury's finding that the statutory aggravating circumstance or statutory aggravating circumstances defined in section sixty-nine outweigh the statutory or other mitigating circumstance or statutory or other mitigating circumstances or (4) the sentence of death is excessive or disproportionate to the penalty imposed in other similar cases of one or more jurisdictions legally authorized to impose said penalty of death, with the greater weight of such comparison to be given to similar Massachusetts cases in which the death penalty will have been imposed, with due consideration of both those cases in which a sentence of life imprisonment was imposed and those cases in which a sentence of death was imposed, or in the event that the court determines any or all of the four factors as enumerated in this section exist, the court shall (1) reverse the sentence of death and remand for a new presentence hearing pursuant to section sixty-eight of chapter two hundred and seventy-nine, or (2) reverse the sentence of death and remand to the superior court department of the trial court for sentence of imprisonment in the state prison for life. The court shall also have the authority to affirm the sentence of death.