The Supreme Court will hear Ellingburg v. United States in October 2025 to decide whether the Constitution's ex post facto ban applies to criminal restitution orders. The case tests how far the clause reaches in protecting people from retroactive punishment.
The Constitution bans ex post facto laws—statutes that criminalize conduct that was legal when it occurred, increase punishment for existing crimes, or change evidence rules to make conviction easier. In Lynce v. Mathis (1997), Florida canceled a prisoner's early release credits after he'd already been released, then rearrested him. The Supreme Court ruled this violated the Ex Post Facto Clause because it retroactively increased his punishment.