Criminal Law Basics

Criminal law differs from civil law in that a criminal offense is against the public, whereas a civil action happens because of a private injury. Local, state, and federal governments have laws that define prohibited acts that cause harm to the public health, safety, or morals. Only the government can prosecute a crime and punish a wrongdoer.

The major steps in a criminal case include investigation, arrest, prosecution, arraignment, plea bargaining, jury trial or bench trial, sentencing, and punishment. When the police suspect a crime has been committed, they investigate to gather evidence and identify a suspect. Sometimes these investigations require a search of a person or place with a warrant, which is a court document that allows police to make an arrest or search a location. The 4th Amendment protects citizens against unreasonable searches and seizures by the government. If the investigation leads to a suspect, the police can arrest the suspect if they have probable cause, meaning that a reasonable connection between the suspect and the crime exists. When a suspect is arrested, the suspect must be informed of their legal rights, referred to as Miranda rights, which was determined by the U.S. Supreme Court in 1966 in Miranda v. Arizona. Once a suspect is arrested, the prosecutor decides whether to charge them with a crime. A suspect becomes a defendant either when they are indicted by a grand jury or when a prosecutor files information. A grand jury is a group of citizens, selected by a court, that determines whether there is enough evidence to charge a person or corporation with a crime. It can include up to 23 jurors who are selected to determine if there is enough evidence of wrongdoing. If the grand jury finds enough evidence, it returns an indictment—an official accusation or charge of a serious crime. An information is an accusatory complaint presented in front of a judge in what is called a preliminary hearing. The judge determines whether probable cause exists to believe that the defendant committed the crime. Once formally charged with a crime, the defendant is arraigned, a process in which they attend court and enter a plea. Sometimes the prosecutor will offer the defendant a plea bargain, in which the defendant pleads guilty in exchange for a lesser charge or shorter sentence. If no plea bargain is made, the defendant goes to trial by a judge, called a bench trial, or a trial by jury as provided by the 6th Amendment. A jury is a group of people, usually 12, who are sworn to give a verdict based on evidence presented. The trial results in the defendant either being acquitted or found guilty. If found guilty, the defendant proceeds to the sentencing phase. Possible sentences include a fine, restitution, community service, probation, house arrest, incarceration in a jail or prison, deportation, and the death penalty.

A defendant charged with a crime is presumed to be innocent. The prosecution bears the burden of proof to prove the defendant's guilt beyond a reasonable doubt. The burden of proof is the prosecution's responsibility to prove the charged offense and the defendant's responsibility to prove a defense if they decide to present one. The prosecution has two burdens: the burden of production to present evidence of the defendant's guilt and the burden of persuasion to convince the trier of fact that the defendant is guilty beyond a reasonable doubt. To sustain a conviction, the prosecution's evidence must prove the defendant is guilty, beyond a reasonable doubt, of every element of the charged offense. This standard of proof beyond doubt is the highest and most challenging burden of proof in any legal context. Once the prosecution has met this burden, the burden shifts to the defendant to raise a doubt or present a defense. However, the defendant is not required to present evidence or a defense.

The prosecution's burden of proof is satisfied when it presents sufficient evidence to prove its case. For example, in an armed robbery case, the prosecution's evidence may include witness testimony, video surveillance, fingerprints, a weapon, and even the defendant's confession. The standard the state's evidence must meet is beyond a reasonable doubt, which is often taken as 99.9 percent certainty that the defendant committed the charged offense. However, it is the trier of fact's role to determine what beyond a reasonable doubt actually means and whether the state's evidence is sufficient to convict, as it can vary on a case-by-case basis. Thus, juries are not instructed on the definition of beyond a reasonable doubt.

The trier of fact, either a judge in a bench trial or a jury in a jury trial, determines whether a party met its burden of proof at trial. The state's burden of proof is always beyond a reasonable doubt, but a defendant's burden of proof for presenting different defenses varies by jurisdiction. For the state to satisfy its burden, it formally presents evidence of the defendant's guilt to the trier of fact. When a party wishes to admit certain evidence for consideration, the judge determines whether it is admissible under the applicable rules of evidence. Generally, evidence is admissible as long as it is relevant, not unfairly prejudicial, not confusing, not a waste of time, not privileged (in other words, not secret and legally protected), and not based on inadmissible hearsay (an out-of-court statement). Evidence comes in two forms: direct and circumstantial. Direct evidence connects the defendant to the crime without the need for any inference. Circumstantial evidence, also called indirect evidence, implies that the defendant committed the crime. Evidence can be anything that supports the truth, either guilt or innocence, and comes in many forms. However, evidence most commonly appears in the form of testimony—a spoken or written statement made in court—from witnesses, documents, physical evidence, and scientific evidence.

Crimes can be broken down into elements, which the prosecution has the burden of proving beyond a reasonable doubt. The elements of each offense are set forth in the criminal statute—in other words, the written law—that the defendant is charged with violating. Every crime has at least two elements: an act or omission when one has a legal duty to act and criminal intent.

The defendant's criminal act must be voluntary. An act is voluntary when the defendant had control over the act or omission. Examples of acts that are not voluntary, and therefore that do not satisfy this element, include reflexes, convulsions, bodily movements during unconsciousness or sleep, and conduct during hypnosis. The defendant's status in society (such as being a sufferer of drug addiction, for instance) and their criminal thoughts are not considered criminal acts and do not satisfy this element. On the other hand, intentionally or accidentally drinking too much and taking excessive drugs are illegal activities because of their reckless nature, even as suffering from an addiction is alone not enough to prosecute.

This element can also be satisfied when the defendant failed to act when they had a legal duty to act under special circumstances. A person has a legal duty to act only when the law imposes that duty by statute, when the duty is created by contract, or when there is a special relationship between the parties.

Examples of when a person has a duty to act based on a statute include the filing of tax returns or the duty to report child abuse. An example of when a person has a contractual duty to act includes a physician's duty to help a patient. However, a physician who is not contractually bound does not have a legal duty to act.

A special relationship exists, invoking a legal duty to act, for parent-child, spouse-spouse, and employer-employee relationships. The guilty mind, also called mens rea, is the criminal intent. A defendant need not know that their conduct is illegal to be guilty of a crime. Instead, the defendant only needs to be aware of their conduct.

The Model Penal Code was published in 1962 and was written to assist U.S. state legislatures in revising and codifying the criminal law of the U.S. It categorizes the required level of intent for a crime by its seriousness, which corresponds to harsher punishment. The first level requires the defendant to act negligently, meaning that they were not aware of the risk but should have been. The second level requires the defendant to act recklessly, meaning that they consciously disregarded a substantial and unjustifiable risk. The third level requires the defendant to act knowingly, meaning they are practically certain that their conduct will cause a particular result. The fourth level requires the defendant to act purposefully, meaning that they intended to act. Crimes classified as strict liability do not require any state of mind and the prosecution need only prove that the defendant committed the offense (the actus reus).