Crimes require a culpable mental state called "mens rea," which is Latin for a "guilty mind." "Mens rea" refers to the defendant's state of mind and criminal intent when they commit a criminal act. Mens rea, along with actus reus, are elements of the crime that must be proven beyond a reasonable doubt.
Mens rea allows the criminal justice system to differentiate between someone who did not mean to commit a crime and someone who intentionally set out to commit a crime.
To give an example, imagine two drivers who end up hitting and killing a pedestrian.
Driver 1 didn't see the person until it was too late and tried their best to brake. However, they could do nothing to stop the accident. In fact, they ended up killing the pedestrian. Driver 1 is still liable, but likely only in civil court for monetary damages, unless Driver 1 was driving recklessly.
Driver 2, on the other hand, had been out looking for the pedestrian and upon seeing them, hit the gas pedal, and slammed into them. The driver killed the pedestrian instantly. Driver 2 is criminally liable because they intended to kill the pedestrian, or at least intended to cause serious bodily harm.
Under the legal concept of "mens rea," the intent of each driver was very different. As a result, their punishments will be different.
Negligence and Recklessness
Carelessness is generally referred to as "negligence" in legal terminology. It typically results in civil liability. However, carelessness can turn into something characterized by a higher level of culpability. Some jurisdictions have criminal statutes with heightened negligence standards. These heightened negligence standards are criminal negligence or reckless negligence.
Negligence in a civil case requires a deviation from the standard of care that a reasonable person would meet. But negligence in a criminal case requires a gross deviation from the standard of care that a reasonable person would meet. Reckless negligence is when the defendant disregards a substantial and unjustifiable risk.
Intentional vs. Unintentional
Intentional harmful behavior is often criminal, but unintentional harmful behavior comes in two basic forms. The first is "mistake in fact," and the second is "mistake of law."
"Mistake in fact" means that, although your behavior fits the definition of a crime in the objective sense, you were acting based on mistaken knowledge.
For example, a person could be selling drugs but mistakenly believe that they are just selling a bag of baking soda. As a result, that person likely lacks the necessary mens rea or mental intent necessary under a drug law, because they never intended to sell an illegal drug. They intended just to sell baking soda, although few people would likely believe that you honestly thought baking soda could be sold for that much money.
"Mistake of law," however, will almost never save you from criminal liability. You've probably heard the phrase that "ignorance of the law is no excuse." That's exactly how the law sees it.
Using the example above, "mistake of law" would be if the person knew that they were selling cocaine, but honestly believed that it was legal to do so. Unlike "mistake of fact," this would not relieve you of liability.
This may seem slightly unfair. However, allowing ignorance of the law as a defense would discourage people from learning the law and undermine the effectiveness of the legal system.
Strict Liability Laws: No Mens Rea Required
Finally, there are some criminal laws that don't require any mens rea or mental state. Strict liability crimes apply to certain acts which entail criminal punishment regardless of intent, usually those involving minors. This is best illustrated by statutory rape laws, which punish the act of having sex with a minor even if the perpetrator honestly thought that the minor was over 18 years of age. Another example of a strict liability offense is the sale of alcohol to minors, which does not require the requisite mens rea. If a gas station clerk sells alcohol to a minor but truly believes the minor is over 21, this will not save the clerk from criminal liability.
Committing a Crime 'Knowingly'
Many criminal laws require a person to "knowingly" engage in illegal activity. The element of the offense that needs to be done knowingly depends on the crime. For example, a drug trafficking law might require that the person knowingly import an illegal drug into the United States. If the defendant had been given a gift to deliver to someone in the U.S., and the defendant honestly did not know that the gift contained an illegal drug, then the necessary mens rea or mental state did not exist. In that case, no illegal act was committed.
Committing a Crime 'Maliciously' or 'Willfully'
Some criminal laws use the terms "malicious" and "willful" to describe certain types of required mens rea. However, under some circumstances, such terms share similar meanings with what "intentionally" and "knowingly" already refer to. In some murder statutes, the required mens rea is a heightened form of intention or knowledge and will result in a higher degree murder charge. The difference is that it is one thing to get mad at someone and kill them in passion, but it's quite another thing to devise an elaborate plan to stalk and kill a victim.
Committing a Crime With 'Specific Intent'
A person commits a specific intent crime when they commit a crime with a particular intent. In contrast, a general intent crime requires the intent to commit an illegal act but without the wish or specific intent for the consequences that result from the act.
An easy-to-understand example of a specific intent crime is theft. Most theft statutes require that you not only take some object (the physical act) but that you take it with the intent to deprive the rightful owner of that object permanently. For example, imagine that you took your friend's pair of sunglasses for the day, but you did so with the intent to give them back later that afternoon. You had no right to take those glasses because they belong to your friend. However, you didn't commit theft because you never had the intention of permanently keeping the sunglasses.
Why Motive Matters
Motive is an indirect way to prove that something was done intentionally or knowingly. For example, a defendant in an assault case may claim that they punched the victim by accident and thus didn't have the necessary intent for an assault. If the prosecution can demonstrate that the defendant and victim had been arguing shortly before the alleged assault, that motive can serve as circumstantial evidence that the defendant really did intend to punch the victim. Alternatively, defendants can use the prosecution's lack of evidence of a motive as reasonable doubt to avoid criminal liability.
Get Legal Help Understanding Mens Rea
As you can see, intent or mental state plays a significant role in the criminal justice system. It is often an element that must be proven in any criminal case. If you're facing criminal charges, it's a good idea to contact an experienced criminal defense attorney who can help you evaluate and challenge the evidence against you.