In Schriro v. Summerlin (2004) 542 U.S. 348, the Supreme Court revisited Teague v. Lane (1989) retroactivity analysis. The Schriro court defined 0 the key distinction in the retroactivity analysis as whether the new rule is substantive or procedural. Schriro held that substantive rules apply retroactively, and include those rules that (1) narrow the scope of a criminal statute by interpreting its terms or (2) alter the range of conduct or the class of persons covered by the statute and place them beyond the State's power to punish. (Schriro, supra, 542 U.S. at pp. 351-352.) Included within the second category are rules prohibiting a certain category of punishment for a class of defendants because of their status or offense. Such rules apply retroactively because they carry a "'significant risk'" that a defendant stands convicted of "'"an act that the law does not make criminal"'" or "faces a punishment that the law cannot impose upon him." (Id. at p. 352.) The court explained that although it had sometimes referred to rules of this type as "falling under an exception to Teague's bar on retroactive application of procedural rules, ... they are more accurately characterized as substantive rules not subject to the bar." (Id. at p. 352, fn. 4, citation omitted.) The court further explained that new "rules of procedure" generally do not apply retroactively because they do not produce a class of persons convicted on conduct that the law does not make criminal, but merely raise the possibility that someone convicted with use of the invalidated procedure might have been acquitted otherwise. The court found that because of the speculative connection to innocence, retroactive effect is only given to a small set of "'"watershed rules of criminal procedure"'" implicating the fundamental fairness and accuracy of the criminal proceeding. (Schriro, supra, 542 U.S. at p. 352.) This class of rules is extremely narrow; a watershed rule is one "'without which the likelihood of an accurate conviction is seriously diminished.'" (542 U.S. at p. 352.)