Mens-Rea It means “guilty mind”. It is one the element in the commission of crime. It is the state of mind where one is sure enough that it will conjure crime.
Nulla Pena lege it is a Latin word which means no penalty without law it is a legal principle which requires that no one can be punished if he or she did any that act which are not prohibited under the law.
This doctrine basically dictates the courts to look at the similar judgments under similar circumstances that have been passed.
Executive privilege is the right of the president of the United States and other members of the executive branch to maintain confidential communications.