How Defendants' Mental States Affect Their Responsibility for a Crime

What makes a crime a crime? In most cases, an act is a crime because the person committing it intended to do something that the state legislature or Congress has determined is wrong, also known as criminal intent. This mental state is generally referred to as "mens rea," Latin for "guilty mind."

What Is Mens Rea?

The "mens rea" concept is based on the belief that people should be punished only when they have acted in a way that makes them morally blameworthy. In the legal system's eyes, people who intentionally engage in behavior prohibited by law are morally blameworthy. For example, it's a crime to intentionally shove someone down a set of stairs and injure that person. But it's not a crime to trip and fall and accidentally push someone down a set of stairs as a result of falling.

Defining Criminal Intent

The Model Penal Code divides criminal intent into four mental states: purposely, knowingly, recklessly, and negligently.

Acting Intentionally or Purposely

Most crimes require a prosecutor to prove the defendant acted intentionally or purposely. These terms mean the person acted with the intent or purpose of causing the specified result. For example, a defendant commits assault by intentionally inflicting bodily harm to another. Punching someone in the face and causing a bloody nose is an intentional act that caused harm.

Acting Knowingly

Some laws punish violators who knowingly engage in illegal conduct, meaning they believe the specified facts exist or are aware that their conduct will cause a certain result. What a person has to "know" to be guilty of a crime depends on the behavior that a law makes illegal. For example:

• A drug law makes it illegal for a person to "knowingly" import an illegal drug into the United States. To convict a defendant of this crime, the prosecution would have to prove that a defendant knew that what he brought into the United States was an illegal drug.
• Another drug law makes it illegal to furnish drug paraphernalia with "knowledge" that it will be used to cultivate or ingest an illegal drug. To convict a defendant of this crime, the prosecution would have to prove that a defendant who sold or supplied drug paraphernalia knew about the improper purposes to which the paraphernalia would be put.

Acting With Criminal Negligence or Recklessly

"Ordinary" carelessness is not a crime. For example, careless ("negligent") drivers are not usually criminally prosecuted if they cause an accident, though they may have to pay civil damages to those harmed by their negligence.

However, more-than-ordinary carelessness ("recklessness" or "criminal negligence") can amount to mens rea. Acting recklessly means the defendant acted while consciously disregarding a substantial and unjustifiable risk of harm. Criminal negligence is a step below reckless. It means the defendant acted when they should have been aware of a substantial and unjustifiable risk of harm.

An example of reckless conduct might be shooting a gun near someone to scare them and hitting the person. Shooting a gun anywhere near people is a substantial and unjustifiable risk of harm. An act of criminal negligence could be a driver showing off by whipping donuts in a car on a public street and hitting a pedestrian, even though he thought no one was around. Most people would realize that it's very dangerous to do dangerous maneuvers with a vehicle while on a public street that anyone can use.

It's up to judges and juries to evaluate a person's conduct according to community standards and decide whether the carelessness is serious enough to demonstrate mens rea.

What Does It Mean If a Crime Requires "Malicious" or "Willful" Behavior?

In everyday usage, people often use the term "malicious" to mean "spiteful" or "wicked." In most criminal statutes, however, "malicious" is synonymous with "intentional" and "knowing." As a result, the term "maliciously" usually adds nothing to the general mens rea requirement.

As used in murder statutes, however, the term "malice" is often interpreted as meaning the defendant had a "man-endangering" state of mind when the act was committed, which is enough to justify at least a second-degree murder charge.

As with "maliciously," the term "willfully" usually adds nothing to the general mens rea requirement. At times, however, the term "willfully" in a statute has been interpreted to require the government to prove not only that a person acted intentionally, but also that the person intended to break the law. (This is an unusual instance in which "ignorance of the law" actually is an excuse!) For example, in one case a federal law made it illegal to willfully bring into the country more than $10,000 in cash without declaring it to customs officials. The U.S. Supreme Court decided that to convict a person of violating this law, the government had to prove that the person knew the law's requirements. (Ratzlaf v. U.S., 510 U.S. 135 (1994).)

What Is a "Specific Intent" Crime?

"Specific intent" laws require the government to do more than show that a defendant acted "knowingly." Specific intent laws require the government to prove that a defendant had a particular purpose in mind when engaging in illegal conduct. (For more, see General Intent Crimes vs. Specific Intent Crimes.)

For example, many theft laws require the government to prove that a defendant took property "with the intent to permanently deprive a person of the property." To convict a defendant of theft, the government has to prove that a thief's plan was to part the victim from their property forever. For example, a culprit who drives off in another's car without permission and returns it a few hours later might be convicted only of "joyriding." However, the same culprit who drives off in another's car without permission and takes it across the country probably demonstrates a specific intent to permanently deprive the owner of the car and would be guilty of the more serious crime of car theft.

Is It a Crime If You Didn't Know the Conduct Was Illegal?

People who unintentionally engage in illegal conduct may be morally innocent; this is known as making a "mistake of fact." Someone who breaks the law because he or she honestly misperceives reality lacks mens rea and should not be charged with or convicted of a crime. For example, if Paul Smith hits Jonas Sack because he reasonably but mistakenly thought Sack was about to hit him, Smith would not have mens rea.

While a "mistake of fact" can negate mens rea, a "mistake of law" usually cannot. Even when people don't realize what they are doing is illegal, if they intentionally commit the act, they are almost always guilty. For example, if Jo sells cocaine believing that it is sugar, Jo has made a mistake of fact and lacks mens rea. However, if Jo sells cocaine in the honest but mistaken belief that it is legal to do so, Jo will have mens rea since she intentionally committed the act. Perhaps the best explanation for the difference is that if a "mistake of law" allowed people to escape punishment, the legal system would encourage people to remain ignorant of legal rules.

Do Any Crimes Not Require Mens Rea (a Guilty Mind)?

Laws that don't require mens rea—that is, laws that punish people who may be morally innocent—are called "strict liability" laws. The usual justification for a strict liability law is that the social benefits of stringent enforcement outweigh the harm of punishing a person who may be morally blameless. Examples of strict liability laws include:

• "Statutory rape" laws, which in some states make it illegal to have sexual intercourse with a minor, even if the defendant honestly and reasonably believed that the sexual partner was old enough to consent legally to sexual intercourse.
• "Sale of alcohol to minors" laws, which in many states punish store clerks who sell alcohol to minors even if the clerks reasonably believe that the minors are old enough to buy liquor.

Strict liability laws like these punish defendants who make honest mistakes and therefore may be morally innocent.

Is Motive the Same as Mens Rea?

No. "Motive" generally refers to the reason behind an illegal act. For example, a person's need to raise money quickly to pay off a bookie may be the motive for a robbery, while revenge for a personal affront may be the motive for a physical attack. Prosecutors often offer motive evidence as circumstantial evidence that a defendant acted intentionally or knowingly. Judges and jurors are more likely to believe that a defendant had mens rea if they know that the defendant had a motive to commit an illegal act. By the same token, defendants may offer evidence showing that they had no motive to commit a crime and then argue that the lack of a motive demonstrates reasonable doubt of guilt.

For More Information

To learn more about every phase of the criminal justice process, see The Criminal Law Handbook: Know Your Rights, Survive the System, by Paul Bergman and Sara Berman (Nolo).