What article of the U.S.Constitution bans ex post facto laws?

Question

What article of the U.S.Constitution bans ex post facto laws?​

Quizplus · Accepted Answer

Article One, Section 9 of the U.S. Constitution explicitly prohibits Congress from passing any ex post facto law. This means that Congress cannot pass a law that retroactively criminalizes conduct that was legal when it occurred, or increases the punishment for a crime after it has been committed. This protection ensures that individuals are not punished for actions that were not considered illegal at the time they were committed.

What Article of the U