Q. Consider the following:

1. Ex Post Facto Law
2. Double Jeopardy
3. Habeas Corpus
4. Nullum Crimen, Nulla Poena Sine Lege

Which of the above principles provide protection against retroactive punishment?
Answer: Only 1 & 4
Notes: Ex Post Facto Law and Nullum Crimen, Nulla Poena Sine Lege both protect against retroactive punishment. Ex Post Facto Law prevents laws that change the legal consequences of actions that were committed before the enactment of the law. Nullum Crimen, Nulla Poena Sine Lege ensures that no one can be punished under a law that did not exist at the time the offense was committed.