This case is about a court’s authority to modify a final criminal judgment. Nearly four decades ago, Pervis Payne received two death sentences for brutally murdering a single mother and her two-year-old daughter. Because of the possibility that the death sentences might be commuted to life sentences in future proceedings, the court aligned the sentences to be served consecutively. Years later—after this Court held that the execution of persons with intellectual disabilities violates the federal and state constitutions, see Van Tran v. State, 66 S.W.3d 790, 812 (Tenn. 2001)—the Tennessee legislature established a procedure whereby certain death-sentenced inmates could receive an intellectual disability determination to evaluate the constitutionality of their sentences. Tenn. Code Ann. § 39-13-203(g) (2021). Payne made use of that pathway and was adjudicated intellectually disabled. The trial judge presiding over that adjudication vacated Payne’s death sentences and imposed two life sentences in their place. But the court did not stop there: it also revisited the earlier consecutive sentencing determination and ordered that Payne’s sentences be served concurrently instead, which would make Payne eligible for parole in 2026. We hold that the trial court lacked jurisdiction to realign Payne’s sentences. Once a criminal judgment becomes final, it may not be modified unless a statute or rule authorizes its modification. The trial court had authority to adjudicate Payne intellectually disabled under Tennessee Code Annotated section 39-13-203(g). It also had authority to vacate Payne’s death sentences and substitute sentences of life imprisonment under Tennessee Code Annotated section 39-2-205(e) (1982). No statute or rule, however, gave the trial court authority to realign Payne’s sentences, so we vacate that part of the trial court’s judgment.