what is mens rea?

In Florida, a three year-old picked up a poorly misplaced pistol and killed his mother by accident. Is the toddler a murderer? No. This is because every crime has at least two parts: the actus reus (bad act) and the mens rea (guilty mind). While the toddler did certainly do something bad, he lacked the mind to think through his actions. The guilty mind lies on a spectrum. Here are the levels of mens rea:


  1. Purpose: Purpose means the same thing as intent. In light of the actus reus, it means that the accused wanted the bad act to happen and went out of his way to make sure it happened. First degree murder is the actus reus of causing death coupled with the mens rea of wanting the victim to be dead. In R v Minassian, the Court found that the perpetrator of the Toronto van attack, Alek Minassian showed purpose when he rented a large van and posted his wish to kill people on Facebook before the attack.


  1. Knowledge: Knowledge means knowing that what you’re doing will cause harm even if your intent isn’t the harm itself. Another way to look at knowledge is the idea of willful blindness. In R v Briscoe, Michael Briscoe drove his friends to a location where they raped and murdered a child. While Briscoe didn’t commit the act of killing himself, he did know what his friends’ intentions were and willfully ignored them.


  1. Recklessness: Recklessness is willfully ignoring a substantial risk. Suppose that it’s 8:55 AM and a businessman is late for his 9:00 AM meeting in downtown Toronto. To make it in time, he drives through the very busy Yonge and Dundas Square at a red light knocking people over. By carelessly running the red light, he shows recklessness to the fact that there are vulnerable people crossing the street. Unlike Alek Minassian, he didn’t want these people to die; he just doesn’t care if they did.


  1. Negligence: Negligence relates to shirking the duties that we have to others. The owner of the ladder company has the duty to make sure that the screws of your ladder don’t fall apart when you’re thirty five feet above ground. Some duties are so important that they’re handled by criminal law. One such duty is the duty that we owe to other drivers on the road. In R v Tschetter, Daniel Tschetter drove his truck into a sedan killing five people. By driving 130 km/h at a red light and ignoring the circumstances, Tschetter behaved in a way that most people wouldn’t on the road. Compared to recklessness, negligence doesn’t need the “I don’t care” attitude of the businessman at Yonge and Dundas, but instead a carelessness that results in harm.


Every crime needs and actus reus and a mens rea. More serious crimes need a higher mental element and showing that you don’t have the necessary mens rea is one way to defend yourself in court. At Ron Ellis Law, we can help with that. We practice criminal defence law all over Southwestern Ontario including Grand Bend, Sarnia, Woodstock, and Kitchener.

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