Id. In Williams v. State, 715 N.E.2d 882 (Ind.Ct.App. 1999), rev'd on other grounds, 737 N.E.2d 734 (Ind. 2000), we noted that, in the past, the terms "law of the case doctrine" and "res judicata" had been used interchangeably. We also noted in Williams that they are two separate concepts: the law of the case doctrine is a discretionary doctrine which is implicated when a litigant asks a court to revisit an earlier decision of its own in a collateral appeal of that decision and expresses the practice of courts generally to refuse to reopen what has been decided. Res judicata provides that a judgment on the merits is an absolute bar to a subsequent action on the same claim between the same parties.
The "law of the case" doctrine mandates that when an appellate court decides a legal issue, both the trial court and the court on appeal are bound by that determination in any subsequent appeal involving the same case and relevantly similar facts. Williams v. State, 715 N.E.2d 882, 886 (Ind.Ct.App. 1999). See also Cha v. Warnick, 476 N.E.2d 109, 114 (Ind. 1985),cert. denied, 474 U.S. 920 (1985).
Both Spradlin and Simmons relied on our earlier decisions in Zickefoose v. State, 270 Ind. 618, 622, 388 N.E.2d 507, 510 (1979) (granting relief on direct appeal), and Smith v. State, 459 N.E.2d 355, 358 (Ind. 1984) (granting relief on direct appeal). On August 10, 1999, the Court of Appeals affirmed the post-conviction trial court's denial of Williams's petition for post-conviction relief. Williams v. State, 715 N.E.2d 882, 888 (Ind.Ct.App. 1999). The Court of Appeals acknowledged that it had been incorrect to reject Williams's Spradlin claim on direct appeal, but it nevertheless held that Williams was not entitled to relief because, as an accomplice, Williams's "intent was not an issue," id., and so the Spradlin rule was not implicated.
The law of the case doctrine mandates that when an appellate court decides a legal issue, both the trial court and the court on appeal are bound by that determination in any subsequent appeal involving the same case and relevantly similar facts. Williams v. State, 715 N.E.2d 882, 886 (Ind.Ct.App. 1999). The doctrine's purpose is to minimize unnecessary relitigation of the legal issues once they have been resolved by an appellate court.