In many criminal cases, the common-law requirement that a defendant must have a mens rea (ie, he must or should know that he is doing wrong) has been weakened or erased.
The trial or petit jury of 12 persons is used in trials of commonlaw, both criminal and civil, except where the right to a jury trial is waived by consent of all parties at law.
In most countries, there are some common elements of justice among national criminal laws and judicial practices, which serve as important guidelines of international criminal law nowadays.