Criminal Law

Criminal Law Basics

By Micah Schwartzbach, Attorney
Learn what a crime is, where crimes come from, and more.

A crime is something that someone does—or doesn’t do—that violates the law and can result in punishment from the government. It's behavior that might harm a specific person but is fundamentally considered an offense against society.

Crimes normally involve an act, like stealing something or striking someone. They occasionally have to do with omission (not doing something). An example is failing to stop, identify oneself, and provide necessary help after a car accident, which is known as hit and run.

Guilty Act and Guilty Mind

Crimes almost always have two core features:

  1. the actus reus, which is a wrongful act or omission, and
  2. the mens rea, which is a culpable state of mind.

To illustrate, under a common definition of perjury,

  1. the actus reus would be making a significant false statement while under oath, and
  2. the mens rea would be knowing that the statement was false.

Creating Crimes

Generations ago, crimes came from common law—decisions developed by judges and courts over time. Today, though, crimes generally come from legislatures, who create statutes that set out offenses and the penalties for them.

Legislatures separate crimes into degrees of severity, with more serious offenses triggering stiffer penalties. In general, statutes set the penalty ranges for offenses and judges set sentences on a case-by-case basis. Statutes can also impose consequences other than standard penalties like jail time and fines; an example is having to register as a sex offender.

Congress defines and sets punishment parameters for federal crimes, while states do the same for most illegal conduct within their boundaries. Some kinds of behavior, like many drug offenses, can be criminal under both state and federal law.

Statutes and Elements

Statutes determine the elements of crimes. Elements are the components of an offense that the government must prove in order to establish the defendant’s guilt.

Court decisions can flesh out or clarify the elements of an offense. For example, the statute that defines theft in California says, “Every person who shall feloniously steal, take, carry, lead, or drive away the personal property of another . . . is guilty of theft.” (Cal. Penal Code § 484(a) (2017).) But the actual elements of the offense are:

  1. taking possession of property someone else owns
  2. taking the property without the owner’s consent
  3. when taking the property, intending to deprive the owner of it permanently (or for long enough that the owner would lose much of its value or enjoyment), and
  4. moving the property even a small distance and keeping it for even a small period of time.

(Judicial Council Of California Criminal Jury Instruction 1800 (2017).)

Kinds of Crimes

There are all kinds of crimes—so many that it would be tough to count. The precise term for any offense will depend on the jurisdiction, as will the elements and penalties. Here are a few general categories and crimes that are often associated with them.

Crimes against people. These are offenses where one person directly harms another. Examples are assault and battery, kidnapping, manslaughter, and murder.

Crimes against property. Property offenses have to do, of course, with some kind of good or service. Property crimes include theft, receiving stolen property, burglary, looting, and forgery. (For more information, see this overview of crimes against property.)

Sex crimes. Offenses falling into the sex-crimes category include rape, statutory rape, prostitution, pimping, and pandering.

Crimes against public order. Many consider drug crimes to be offenses against public order. Prostitution, though listed above, is sometimes referred to as such an offense, too. Other crimes in this category include disorderly conduct, driving offenses, and illegal gambling.

Crimes against the government's authority. All sorts of crimes can be considered transgressions against governmental authority. A few are perjury, bribery, obstruction of justice, and tax evasion.

What ultimately matters about any criminal charge are the statutes defining it and detailing its consequences. If you find yourself facing criminal charges, an experienced criminal defense lawyer should be able to explain the applicable law and advise you of your options.

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