Ex Post Facto — related Supreme Court cases
This page groups Supreme Court cases that involve the constitutional concept “Ex Post Facto”. Use it to explore related decisions and see how the same idea shows up across different cases.
“Ex Post Facto” is:
Prohibition against retroactive criminal laws that disadvantage the accused.
Source: Article I, Section 9, Clause 3 Where this concept definition/label comes from (for example, a constitutional provision or a reference framework).
Cases
These are cases where this concept was identified as relevant. Click a case to view its summary, holding, and supporting syllabus excerpts.
-
Hewitt v. United States
26th June 2025
The case involves the retroactive application of the First Step Act's more lenient penalties to sentences imposed before the Act's enactment.