The Colorado Supreme Court recently issued a decision in Aurora Public Schools v. A.S. finding that the state constitution’s prohibition on retrospective legislation foreclosed civil claims under the Child Sexual Abuse Accountability Act (CSAAA), at least where the statute of limitations had already run prior to the enactment of the CSAAA.[1]

In 2021, Colorado enacted the CSAAA to expand civil remedies for victims of past childhood sexual abuse.[2] Previously, civil tort claims for sexual abuse had been subject to a six-year statute of limitations.[3] For victims who were underaged at the time of the abuse, the six years ran from when the victim turned 18—or in cases where the memories of abuse were repressed into adulthood, from when the victim became able to acknowledge what was done to them.[4] The CSAAA created a new cause of action such that:

A person who was the victim of sexual misconduct that occurred when the victim was a minor and that occurred on or after January 1, 1960, but before January 1, 2022, may bring an action pursuant to this part 12. An action described in this subsection (2) must be commenced before January 1, 2025.[5]

For abuse perpetrated between 1960 and 2022, victims now had a three-year window to sue, even if their claims would have previously been barred by the statute of limitations. For post-January 1, 2022, claims, a separate provision passed by the legislature removed the statute of limitations entirely.[6] In addition, the CSAAA allows claims against not only the perpetrator, but also against the “managing organization” of a “youth-related activity or program” that “knew or should have known” about the abuse.[7] Given that a significant amount of child sexual abuse turns out to be perpetrated by employees of institutions entrusted with the care of children—teachers, coaches, youth-group leaders, etc.—the legislature saw fit to hold those institutions accountable as well.[8] A separate provision waives governmental immunity for public entities such as school districts.[9] 

From 2001 to 2005, A.S. was a student at a public high school in Aurora, Colorado. She alleges that for four years, beginning when she was 14, a coach for the girls basketball and softball teams subjected her to ever increasing levels of sexual abuse, including forcing her to perform oral sex on him more than 100 times.[10] In 2007, she filed a police report, but the police told her the claims were barred by the statute of limitations—incorrectly, as it had only been about three years and the statute of limitations at that time was six years.[11] In 2022, A.S. and her husband B.S. sued the school district and the alleged perpetrator under the new CSAAA.[12] Without the CSAAA, her claims would have been time barred.

The defendants moved to dismiss A.S.’s claims on the theory that the CSAAA’s retroactive application violated article II, section 11 of the Colorado constitution, which provides that “No ex post facto law, nor law . . . retrospective in its operation . . . shall be passed by the general assembly.” The “ex post facto” provision mirrors the ex post facto clauses in the federal Constitution, which likewise bar both the federal and state governments from enacting ex post facto laws.[13] The basic idea is straightforward: laws should not retroactively hold people accountable for things that were not illegal at the time they did them. However, since the Founding era, the U.S. Supreme Court has held that the clauses in the federal Constitution apply only to criminal, and not to civil, statutes.[14] The CSAAA, in providing civil remedies, is therefore not, strictly speaking, an ex post facto law.

But the Colorado constitution bars not just ex post facto laws, but also any law “retrospective in its operation,” and that provision protects against retrospective civil legislation in addition to criminal. And it was pursuant to this retrospectivity clause that the state trial court had dismissed A.S.’s claims, finding that reviving these time-barred torts rendered the CSAAA “retrospective in its operation.” A.S. appealed, and the state supreme court agreed to take up the matter.

After finding the defendants had standing to raise the retrospectivity question,[15] the supreme court took time to clarify exactly what counts as retrospective legislation in Colorado: it “does not mean that any law that applies retroactively is unconstitutional; rather, only certain types of retroactive legislation are unconstitutionally retrospective.”[16] The “prohibition on retrospective legislation prevents the legislature from changing the rules after the fact because to do so would be unjust,” and therefore it is best understood as addressing the same sorts of injustices in the civil context that the ex post facto prohibition prevents in the criminal context.[17]

So what makes a retroactive law retrospective? Colorado follows the “Story definition,” named for early U.S. Supreme Court Justice Joseph Story, whose Commentaries on the Constitution of the United States are a well-respected source for constitutional interpretation.[18] Under this definition, a law is retrospective if it “(1) impairs a vested right; or (2) creates a new obligation, imposes a new duty, or attaches a new disability with respect to transactions or considerations already past.”[19] This definition is disjunctive: either prong is enough to invalidate the statute.

Story’s definition is concerned with substance rather than procedure—that is, the retrospective effect must work its mischief on substantive rights.[20] In Colorado, a law that “takes away any legal defense” is substantive, including a defense that the claim is barred because of the statute of limitations.[21] And that is exactly what CSAAA did in this case: it denied the defendants their defense that the time for A.S. to bring her claims had long since expired. The court did not strike down the CSAAA in its entirety: there are some claims between 1960 and 2022 for which the statute of limitations had not expired, and the court allowed those claims to survive.[22] But if the statute of limitations had run, the CSAAA could not undo that consistent with the state constitution.

In striking down the retrospective effect of the CSAAA, the court did confront the policy implications of its holding. There have been many—often horrifying—stories of institutions over the decades that did too little to prevent abuse, to say nothing of those that actively covered up such atrocities. But, the court explained:

We clarify today that there is no “public policy exception” to the ban on retrospective laws in article II, section 11 of the Colorado Constitution. If the constitutional proscription in article II, section 11 were required to yield to the policy preferences of the legislature, there would be no proscription at all; the legislature could make any retrospective law constitutional simply by proclaiming that the law serves a legitimate government interest.[23]

In any retrospective effort to do justice, there may be good arguments as to why justice demands we skirt this or that limitation on state power. But there will always be a reason why the legislature believes this retrospective law is particularly important. For the rule to hold, the court held, it must apply even when the policy outcome is unsavory.

For better or worse, the Colorado Supreme Court has rejected policy exceptions to the retrospective effect of laws. This is a challenge for those looking to right past wrongs, including those that might only now come to light. Not all states have this same retrospective limitation to civil liability—the court itself notes that states like New York have enacted such laws without constitutional limitation.[24] But in states where retrospective civil liability is constitutionally barred, there may well be limits on what the law can do to right past wrongs.


[1] 2023 CO 39, 531 P.3d 1036 (2023).

[2] 2021 Colo. Sess. Laws 2923.

[3] Aurora Public Schools, 2023 CO at ¶ 6.

[4] Id.

[5] Colo. Rev. Stat. § 13-20-1203(2).

[6] Colo. Rev. Stat. § 13-20-1203(1).

[7] Colo. Rev. Stat. § 13-20-1202(1)(b).

[8] Aurora Public Schools, 2023 CO at ¶ 10.

[9] Colo. Rev. Stat. § 13-20-1207.

[10] Aurora Public Schools, 2023 CO at ¶ 16.

[11] Id. at ¶ 17.

[12] Id. at ¶ 18.

[13] U.S. Const. art I, § 9, cl. 3; id. at § 10, cl. 1.

[14] Calder v. Bull, 3 U.S. 386, 390 (1798).

[15] Aurora Public Schools, 2023 CO at ¶ 34.

[16] Id. at ¶ 38 (emphasis in original) (citing Ficarra v. Dep't of Regul. Agencies, 849 P.2d 6, 12 (Colo. 1993) (“[U]nder our state constitution, some retroactively applied civil legislation is constitutional, and some is not, and it is helpful to mark this distinction by using the term retrospective to apply only to legislation whose retroactive effect violates the constitutional prohibition.”)).

[17] Id. (citing Van Sickle v. Boyes, 797 P.2d 1267, 1271 (Colo. 1990) (“The purpose of the constitutional ban of retrospective legislation . . . is to prevent the unfairness that results from changing the legal consequences of an act after the act has occurred.”); People v. D.K.B., 843 P.2d 1326, 1329 n.2 (Colo. 1993) (“It is well settled . . . that the purposes of the provision forbidding ex post facto laws and the provision forbidding retrospective laws are similar; both seek to prevent unfairness in altering the legal consequences of events or transactions after the fact.”)).

[18] Id. at ¶ 40.

[19] Id. (citing Specialty Rests. Corp. v. Nelson, 231 P.3d 393, 399 (Colo. 2010); Ficarra, 849 P.2d at 15-16).

[20] Id. at ¶ 41.

[21] Id.

[22] Id. at ¶ 53.

[23] Id. at ¶ 48.

[24] Id. at ¶ 38 n.12 (citing Consol. Edison Co. of N.Y. v. State Bd. of Equalization & Assessment, 120 Misc. 2d 617 (N.Y. Sup. Ct. 1983) (“It is well settled that retrospective legislation is prohibited by neither the Federal nor the New York State Constitution, so long as it does not violate the general standards of due process and equal protection.”) (citation omitted)).

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