Article II, section 11 of the Colorado provides that,
No ex post facto law, nor law impairing the obligation of contracts, or retrospective in its operation, or making any irrevocable grant of special privileges, franchises or immunities, shall be passed by the general assembly.
Bans on ex post facto laws have long been interpreted as applying only to criminal statutes (see, e.g., Calder v. Bull (1798)), but the Colorado Supreme Court had held that bans on retrospective laws also extend to lawsuits dealing with civil liability; and while deciding what counts as a “retrospective” law can be complicated, the court had held that revival of claims on which the statute of limitations had expired is indeed impermissibly “retrospective.” In yesterday’s Aurora Public Schools v. A.S., the court unanimously held (in an opinion by Justice Monica Márquez) that the Colorado Legislature’s revival of time-barred sexual assault claims was thus unconstitutional. And it added,
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. Such a back-end rational-basis balancing of an otherwise unconstitutional law against the public interest would render the retrospectivity clause meaningless. This cannot be.
For a similar decision under the Utah Constitution’s general due process principles, see Mitchell v. Roberts (Utah 2020); see also Doe A. v. Diocese of Dallas (Ill. 2009) and Doe v. Roman Catholic Diocese (Mo. 1993). For decisions upholding such retroactive revival of time-lapsed sexual assault claims under general due process principles, see A.B. v. S.U. (Vt. 2023) and the cases that it cites.