← The hardest concepts in United States law
In one breath
Most crimes require a guilty mind as well as a guilty act, and the Model Penal Code sorts the mental states into four levels: purpose, knowledge, recklessness and negligence. Each element of an offense can require its own level, and the level decides what the prosecution must prove about what the defendant was aware of.
The picture
The pot left on the stove
You leave a pot on the stove and go out. Whether you are to blame for the fire depends on what was in your mind. If you meant to start a fire and left the pot to do it, you acted with purpose. If you did not want a fire but were certain the pot would boil dry and burst into flames, you acted with knowledge. If you knew a fire was a real risk and went out anyway, you were reckless. If you never thought of it, but a careful person in your position would have, you were negligent.
The four are a ladder of awareness. Purpose and knowledge look at what you wanted or were sure of. Recklessness requires that you consciously disregarded a substantial and unjustifiable risk. Negligence needs no awareness at all, only a failure to see a risk that a reasonable person would have seen. The higher the rung the offense demands, the more the prosecution must show about what went on in your head.
Where the picture stops working
A stove has one result, while a crime has several elements, each of which can call for its own mental state: the conduct, the result, and the surrounding circumstances. And the pot says nothing about offenses that require no mental state at all, such as strict liability offenses, or about the older common-law labels of general and specific intent, which do not map neatly onto the four levels.
How it really works
- 1Break the offense into elements: the conduct, any result and any attendant circumstances.
- 2For each element, find the required level of culpability, from the statute’s wording. If the statute is silent, the Model Penal Code supplies recklessness as the default for elements of an offense.
- 3Match the facts to the definition. Purpose: a conscious object to engage in the conduct or cause the result. Knowledge: awareness that the conduct is of that nature or that the circumstances exist, or practical certainty that the result will follow.
- 4Recklessness: conscious disregard of a substantial and unjustifiable risk. Negligence: failure to perceive such a risk where the failure is a gross deviation from the care a reasonable person would take.
- 5Ask whether any element is one of strict liability, which needs no mental state, and whether mistake of fact negates the required level.
Why people get it wrong
- Using “intent” as one idea. At common law it can mean purpose or knowledge, and the Model Penal Code uses sharper terms.
- Mixing up recklessness and negligence. The difference is awareness: a reckless person sees the risk and takes it, a negligent person fails to see it.
- Assuming one mental state covers the whole offense. Different elements can demand different levels.
- Equating knowledge with purpose. A person who does not want a result but is practically certain it will follow acts knowingly.
- Forgetting that some modern statutory offenses impose liability without fault. Courts presume that a mental state is required unless the legislature plainly says otherwise (Morissette).
A worked example
The facts are invented
A fictional statute makes it an offense to “damage another’s property by fire”. Four people leave a pot of oil on a stove in a rented room, and each time the apartment burns. Alma wanted the landlord’s property destroyed and lit the stove so it would: purpose. Bruno needed a distraction for a burglary, knew the oil would ignite and left anyway, although he did not want the fire: knowledge. Chen knew the old stove sometimes flared up and went out for an hour regardless: recklessness.
Dara had no idea of the risk, but any careful person would have noticed the frayed gas pipe. She was negligent. Which of the four are guilty depends on the level the statute demands. If it requires at least recklessness, Dara is not guilty; if it criminalizes negligent burning, she is. The Model Penal Code, where it governs, reads silence as requiring at least recklessness.
Try it
A defendant fires a gun into a crowd, hoping to scare the people away. He does not want to kill anyone, but he knows that people may be hit. Which mental state toward the risk of death fits best?
Landmark authorities
Read the sources themselves; this list is a starting point.
- Model Penal Code, section 2.02 (general requirements of culpability)
- Morissette v. United States, 342 U.S. 246 (1952)
- Regina v. Cunningham, [1957] 2 Q.B. 396 (Court of Criminal Appeal, England), on subjective recklessness
Where to go next
More hard concepts in United States law
- Miranda: custody plus interrogation (Criminal procedure)
- Hearsay and its exceptions (Evidence)
This page is an educational overview. It is not legal advice and not a substitute for the sources: the statute, the rule, the case itself. United States law is made in fifty states and in the federal system, and the rules differ between them. Each page states the usual formulation of the rule and names landmark decisions; your own state, circuit or course may use different wording. Check the primary sources before relying on any rule.