You went swimming on Monday. Then, on Tuesday, a law went into effect criminalizing swimming. This would prohibit your prosecution and/or punishment for having swum before there was a law against doing so.

Question

Quizplus · Accepted Answer

Ex post facto laws are laws that apply retroactively, making an action illegal after it was performed. The Constitution prohibits the enactment of ex post facto laws, ensuring that individuals cannot be prosecuted for actions that were legal at the time they were committed.

You Went Swimming on Monday