What is mens rea?
The key to understanding the reasoning behind most criminal statutes is to first understand what the term mens rea means. In Latin, it means “a guilty mind,” and the criminal concept behind it is that, in order to be convicted of a crime, a suspect must have acted with an intent or purpose that makes him or her morally blameworthy. Although you won’t find the term mens rea in most criminal statutes, most crimes require proof of a positive state of mind such as intent, recklessness, or willful blindness. However, it doesn’t matter whether you know that what you were doing was a crime, it only matters that you had the intent to commit the act. The corollary to this, of course, is that if you did commit a crime without intending to (for instance, by mistake) then you do not have a guilty mind, and in most cases you cannot be convicted (remembering, of course, that it is your lawyer’s duty to prove that you had an innocent mind at the time you acted.)
However, there are some laws that do not require mens rea. These are called strict liability crimes.