Criminal Law

The same event can be both. A crime is prosecuted by the government and punished with fines, probation, or imprisonment. A civil wrong, such as negligence, is brought by a private plaintiff who wants money damages. The two systems use different standards of proof:

• Criminal: the prosecution must prove guilt beyond a reasonable doubt.
• Civil: the plaintiff usually must prove the claim by a preponderance of the evidence, more likely than not.

A prosecutor must prove every element of the offense. Most crimes have two core pieces plus a link between them:

• A guilty act (actus reus). Voluntary conduct, or sometimes a failure to act when the law imposed a duty. Thinking about a crime is not a crime.
• A guilty mind (mens rea). The mental state the statute requires, acting purposely, knowingly, recklessly, or negligently.
• Concurrence and causation. The mental state has to accompany the act, and for result crimes the act must have caused the harm.

A few offenses are strict liability, meaning no mental state is required. Speeding is the everyday example: not realizing you were over the limit is not a defense.

A felony is a serious crime generally punishable by more than one year of imprisonment. A misdemeanor is less serious, generally punishable by up to a year in jail, a fine, or both. Many states also have a minor category, often called an infraction or violation, for things like most traffic tickets. Felony convictions can also carry long-term consequences for jobs, housing, and licensing.

Common defenses do not deny that something happened; they explain why it is not a punishable crime:

• Self-defense: a reasonable use of force to stop an immediate threat, and no more force than the situation called for.
• Defense of others or property: similar limits, with less force allowed to protect property.
• Insanity: a mental illness that prevented the defendant from understanding the nature or wrongfulness of the act. Rarely raised and rarely successful.
• Duress: the defendant acted because of an immediate threat of serious harm.
• Mistake of fact: an honest mistake that negates the required mental state.
• Entrapment: government agents induced a person to commit a crime they were not otherwise disposed to commit.

Several constitutional protections apply from the first police contact through appeal:

• Fourth Amendment: freedom from unreasonable searches and seizures. Evidence obtained unlawfully can often be excluded.
• Fifth Amendment: the right to remain silent, protection against double jeopardy, and due process.
• Sixth Amendment: the right to a lawyer, a speedy and public trial, an impartial jury, and to confront witnesses.
• Eighth Amendment: no excessive bail or fines and no cruel and unusual punishment.