One reason that the mens rea concept is so complex is that courts and legislatures use varying and confusing terminology to describe it.

Purposely, designedly, knowingly, willfully, intentionally, with premeditation, etc.

For example, most people don’t break into other peoples houses at night without the intent to steal something.

We can know indirectly what people intend by observing directly what they do.

Legislatures and courts don’t use the same term to define mens rea—the US Criminal Code uses 79 separate words and phrases to define mens rea.

All of these terms, however, can be boiled down into four states of intent: general, specific, transferred, and constructive.

Applies to crimes of cause and result.

So, in addition to the intent to commit the criminal act, specific intent includes the intent to cause a particular result, such as a homicide, which requires the intent to cause death.

Refers to cases in which actors cause harms greater than they intended or expected.

Driving above the speed limit on an icy road and killing someone by losing control of the vehicle can establish the constructive intent to kill.

The model penal code has established four levels of culpability, arranged from most to least blameworthy:

MPC: "A person acts purposely with respect to a material element of an offence when:

"i. if the element involves the nature of his conduct or a result thereof, it is his conscious object to engage in conduct of that nature or to cause such a result."

A person acts knowingly when:

i. If the element involves the nature of his conduct…he is aware that his conduct is of that nature…and

ii. If the element involves a result of his conduct, he is aware that it is practically certain that his conduct will cause such a result.

A person acts recklessly with respect to a material element of an offense when he consciously disregards a substantial and unjustifiable risk that the material element exists or will result from his conduct.

A person acts negligently with respect to a material element of an offense when he should be aware of a substantial and unjustifiable risk that the material element exists or will result from his conduct.

Purpose in mens rea is roughly the same as the everyday saying "you did that on purpose."

The specific intent either to engage in crimes of criminal conduct or to act with the conscious object of causing a particular result in crimes of cause and result.

In murder, for example, the murderer’s "conscious object" is the victim’s death.

You cant intend to do harm without knowing it, but you can knowingly cause harm without intending it.

Example: A surgeon who removes the cancerous uterus of a pregnant woman knowingly kills the fetus in her womb; but killing the fetus is not the purpose (conscious object) of the removal.

Most jurisdictions apply a subjective standard to determine whether defendants intentionally or knowingly engaged in conduct or caused harmful results.

Some jurisdictions do use an objective standard.

Subjective: Asks what the defendant actually intended or knew.

Objective: Asks what a reasonable person would have intended or should have known.

Reckless people consciously (knowingly) create risks of harm—they don’t intend to cause harm itself.

Recklessness deals with probabilities; purpose and knowledge deal with certainties.

Recklessness requires more than awareness of ordinary risks; it requires awareness of substantial and unjustifiable risks.

The American Law Institute has developed a two-pronged test in the Model Penal Code.

Prong 1: Were the defendants aware how substantial and unjustifiable the risks that they disregarded were?

Note that the risk most be both substantial and unjustifiable—a surgeon who performs a risky operation to save a person’s life is not unjustified.

Prong 2: Does defendants’ disregard of risk amount to so "gross a deviation from the standard" that a law-abiding person would observe in the situation?

This prong asks juries to determine if the risk was substantial and unjustifiable enough to merit criminal punishment.

Negligence is the creation of unconscious risk.

The test is entirely objective: the actor should have known about the risk but did not.

Traditionally, criminal liability requires some degree of blameworthiness—culpability.

But in a large number of minor offenses, culpability is not required.

These are called strict liability offenses—criminal liability without mens rea.

Many argue that the potential for injustice is mitigated by the fact that such offenses are relatively minor, usually only resulting in fines.

Others argue that strict liability crimes are inherently unjust and violate a basic tenant of our legal system.

The idea that mens rea has to come before actus reus.

Burglary, for example, requires that the intent to steal set in motion the act of breaking and entering.

If you broke into a cabin in a blizzard to keep from freezing to death with the permission of park rangers, then decided to steal state property once inside, concurrence is not present.