Elements of an offense: the prohibited act

Professor Desjardins opens week three with a photograph of a set of car keys on a kitchen table. A man has been drinking heavily at home. His car is in the driveway and the keys are on the table, ten meters away. Is he committing an offense? The class says no. Now, the professor says, imagine he is asleep behind the wheel with the engine running to keep warm. Now imagine he is driving. Somewhere along that sequence, conduct that the law does not care about becomes conduct that it punishes, and the line is drawn by the words of the offense. Every offense is built from elements, the specific facts the prosecution must prove, and the first group of elements describes what the accused did. Lawyers call it the actus reus, Latin for the guilty act. This lesson is about that group of elements and about how officers gather evidence of each one.

The building blocks of every offense

Criminal liability usually requires two things at the same time: a prohibited act and a guilty state of mind. The second element, called mens rea or the guilty mind, is the subject of lesson 4. The two must coincide, meaning the guilty mind must exist at some point during the guilty act. A man who accidentally knocks someone down the stairs and then, seeing the person injured, is glad, has not committed an assault: he had no guilty mind when he acted. Courts apply this requirement sensibly, however. When an act continues over time, as when a driver accidentally parks on a police officer's foot and then refuses to move, the guilty mind can arise during the continuing act, as an English court held in Fagan v. Metropolitan Police Commissioner (1969), a case still taught in both countries.

The actus reus of an offense can have three parts. The conduct is what the accused did or failed to do, such as taking, touching, entering or driving. The circumstances are facts that must exist for the conduct to be criminal, such as that the property belonged to someone else, that the person touched did not consent, or that the victim was a peace officer. The consequences are results that the conduct must cause, such as death, bodily harm or damage. Not every offense has all three. Some offenses, sometimes called conduct crimes, are complete as soon as the act is done, whatever its result: making a threat is complete when the words are communicated, whether or not the victim is frightened. Others, called result crimes, require a consequence: homicide requires a death, and felonious assault requires an injury. Breaking an offense into these parts tells an investigator exactly what facts to prove.

The act must be voluntary

The criminal law punishes conduct that is the product of a person's will. A reflex, a spasm, a movement during an epileptic seizure, or an act done while sleepwalking is not a voluntary act, and there is no actus reus. The Model Penal Code, section 2.01, says a person is not guilty of an offense unless liability is based on conduct that includes a voluntary act, and lists reflexes, convulsions, movements during unconsciousness or sleep, and conduct under hypnosis as not voluntary. Ohio's criminal code, section 2901.21, likewise requires a voluntary act, or an omission to perform an act or duty the person is capable of performing, and says reflexes, convulsions, body movements during unconsciousness or sleep and body movements that are not otherwise a product of the actor's volition are involuntary. Involuntariness is rare in practice and usually raised by the defense with medical evidence, but it explains why officers record details such as whether a person appeared conscious, confused or responsive.

Voluntariness is judged at the right moment. A person who knows she has untreated epilepsy and drives anyway may be liable for a crash during a seizure, because the voluntary act was choosing to drive. Self-induced intoxication is usually treated differently from automatism, under special rules covered in lesson 11. And the act need not be the final movement. A person who sets a timer on a fire-starting device and walks away has acted voluntarily, even though he is miles away when the fire starts.

Omissions: when failing to act is a crime

As a general rule, the criminal law does not punish people for failing to help. A passer-by who watches a stranger drown without lifting a finger may be morally contemptible but commits no crime in most cases. A failure to act becomes criminal only when the law imposes a duty to act. The Model Penal Code, section 2.01(3), says an omission is a basis for liability only if the law defining the offense makes it one or a duty to perform the act is otherwise imposed by law. Courts have traditionally recognized duties in four situations, summarized in Jones v. United States (1962): where a statute imposes a duty, where the person has a special status relationship such as parent and child, where the person has assumed a contractual duty to care for another, and where the person has voluntarily assumed care of another and so secluded the helpless person that others could not help. Ohio's endangering children statute, R.C. 2919.22, for example, makes it a crime for a parent or person in charge of a child to create a substantial risk to the child's health or safety by violating a duty of care, protection or support.

Omission cases often reach police as deaths or near-deaths of children, elderly people or people with disabilities who were left without food, medical care or supervision. Investigating them means proving the relationship that created the duty, what the accused knew about the person's condition and what help was available. Officers should note the condition of the home, the food and medication present, the person's appearance and what caregivers say about their routine, because the case may depend on showing that a reasonable caregiver would have acted.

Possession

Many offenses, especially drug and weapons offenses, are defined by possession rather than an act in the ordinary sense. Possession is a state, not a movement, but the law treats it as a guilty act when the person knows of the item and has control over it. The Model Penal Code, section 2.01(4), treats possession as an act if the possessor knowingly procured or received the thing or was aware of control over it for long enough to have been able to end possession. Ohio defines possession in R.C. 2925.01 as having control over a thing or substance, adding that it may not be inferred solely from mere access to the thing through ownership or occupation of the premises on which it is found. Courts distinguish actual possession, meaning on the person, from constructive possession, meaning the ability to exercise dominion and control over the item and knowledge of its presence, and possession can be joint among several people.

In practice, possession is often the hardest element to prove when an item is found in a shared space. A gun under the front passenger seat of a car with four occupants, a bag of drugs in a kitchen used by five roommates, a knife in the console of a borrowed vehicle: in each case the prosecution must show that a particular person knew the item was there and had control over it. Officers build that proof from details. Where exactly was the item? Whose belongings were near it? Who owns or rents the car or room? Did anyone make a statement, a furtive movement or an attempt to hide it as police approached? Are there fingerprints or DNA on it? Were there texts on a phone about it? Each detail is a brick in the wall of knowledge and control.

Turning elements into an investigation plan

Ms. Liu tells the class that the most useful document in any file is the one most officers never write: a list of the elements of each charge, with the evidence for each one beside it. She shows them a case from last year. A man pushed an officer who was arresting his brother outside a bar. The officer charged assault on a peace officer under R.C. 2903.13, which is a felony of the fourth degree when the victim is a peace officer performing official duties. At trial the defense argued that the officer was not lawfully engaged in her duty because the brother's arrest was unlawful, an element the file barely addressed. The case survived only because the arresting officer's notes happened to record the grounds. The code below shows the checklist approach applied to that charge.

# Elements checklist: assault on a peace officer, R.C. 2903.13(A) and (C)(5)
elements = [
    ("knowingly caused or attempted to cause physical harm", ["officer's notes: pushed with both hands", "bystander video"]),
    ("to another person", ["officer identified; injury photos of scraped elbow"]),
    ("victim was a peace officer", ["uniform, marked car, badge number"]),
    ("officer was performing official duties", ["grounds for the brother's arrest: witness statement"]),
    ("awareness she was an officer (supports knowingly)", []),
]
missing = [name for name, evidence in elements if not evidence]
for name, evidence in elements:
    mark = "OK  " if evidence else "GAP "
    print(f"{mark}{name:54s} {'; '.join(evidence) or 'no evidence recorded'}")
print(f"{len(elements) - len(missing)} of {len(elements)} elements supported; gaps: {missing}")

OK  knowingly caused or attempted to cause physical harm   officer's notes: pushed with both hands; bystander video
OK  to another person                                      officer identified; injury photos of scraped elbow
OK  victim was a peace officer                             uniform, marked car, badge number
OK  officer was performing official duties                 grounds for the brother's arrest: witness statement
GAP awareness she was an officer (supports knowingly)      no evidence recorded
4 of 5 elements supported; gaps: ['awareness she was an officer (supports knowingly)']

The checklist shows a gap: nothing in the file records why the accused would have known the victim was a police officer. In reality the answer is obvious, since she was in uniform beside a marked car, but obvious facts still have to be in evidence. A single line in the notes, such as that the accused looked at the officer, said a crude word about police and then pushed her, closes the gap. Linh points out that the checklist could be built into a records system, prompting officers to record evidence for each element before a charge is submitted. Ms. Liu says several services are trying exactly that.

Circumstances and definitions

Many of the hardest questions in criminal law are about circumstances, and the answers are often in definitions sections. Is a garage an occupied structure for burglary? Ohio's definition in R.C. 2909.01 includes any house, building, outbuilding, watercraft, aircraft, railroad car, truck, trailer, tent or other structure that is maintained as a permanent or temporary dwelling even if temporarily unoccupied, or in which at the time any person is present or likely to be present. A detached garage of a family home is often found to qualify. What is physical harm? R.C. 2901.01 defines it as any injury, illness or other physiological impairment, regardless of its gravity or duration, while serious physical harm requires something more, such as harm involving substantial risk of death, permanent incapacity or acute pain of a duration that results in substantial suffering. Officers who know the definitions avoid two errors: undercharging, because an everyday word seems too narrow, and overcharging, because an everyday word seems broader than the legal one.