Criminal Law Cheat Sheet

The core ideas of Criminal Law distilled into a single, scannable reference — perfect for review or quick lookup.

PiqCue — piqcue.com/criminal-law/cheatsheet

Quick Reference

Mens Rea

The 'guilty mind' element of a crime, referring to the mental state or intent required for criminal liability. The Model Penal Code identifies four levels: purposely, knowingly, recklessly, and negligently.

Actus Reus

The 'guilty act' element of a crime, referring to the physical act or unlawful omission that constitutes the external component of a criminal offense. A mere thought or intention, without an accompanying act, is generally not punishable.

Beyond a Reasonable Doubt

The standard of proof required for a criminal conviction, demanding that the prosecution prove each element of the crime to a level of certainty that leaves no reasonable doubt in the mind of a rational juror.

Due Process

The constitutional guarantee under the Fifth and Fourteenth Amendments that the government must respect all legal rights owed to a person, including fair procedures (procedural due process) and fundamental fairness in the law itself (substantive due process).

Felony vs. Misdemeanor

The two main categories of criminal offenses. Felonies are serious crimes typically punishable by more than one year in prison, while misdemeanors are lesser offenses usually punishable by up to one year in jail and/or fines.

Plea Bargaining

A negotiation between the prosecution and defense in which the defendant agrees to plead guilty to a lesser charge or to one of multiple charges in exchange for a more lenient sentence or the dismissal of other charges.

Self-Defense

An affirmative defense asserting that the defendant used force to protect themselves from an imminent threat of unlawful harm. The force used must generally be proportional to the threat, and in many jurisdictions, the defendant must have had a reasonable belief that force was necessary.

Double Jeopardy

The Fifth Amendment protection that prevents a person from being tried twice for the same offense after acquittal or conviction. This principle ensures finality in criminal proceedings and protects individuals from government harassment through repeated prosecutions.

Strict Liability

A category of criminal offenses that do not require proof of mens rea (criminal intent). The prosecution need only prove that the defendant committed the prohibited act, regardless of their mental state or intent.

Habeas Corpus

A legal writ that requires a person who is detained or imprisoned to be brought before a court so that the legality of their detention can be reviewed. It serves as a fundamental check against unlawful imprisonment by the state.

Key Terms at a Glance

Accomplice:A person who knowingly and voluntarily assists or encourages the principal in the commission of a crime.

Acquittal:A judgment that a criminal defendant has not been proven guilty beyond a reasonable doubt, resulting in release from charges.

Actus Reus:The physical act, unlawful omission, or voluntary conduct that constitutes the external element of a crime.

Arraignment:A court proceeding in which the defendant is formally charged, informed of their rights, and asked to enter a plea of guilty, not guilty, or no contest.

Bail:Money or property deposited with the court to secure a defendant's release from custody and ensure their appearance at future court proceedings.

Burden of Proof:The obligation to prove allegations or claims in a legal proceeding. In criminal cases, this burden falls on the prosecution.

Conspiracy:An agreement between two or more persons to commit a criminal act, combined with an overt act in furtherance of the agreement.

Double Jeopardy:The constitutional prohibition against being tried or punished twice for the same criminal offense after acquittal or conviction.

Due Process:The constitutional requirement that legal proceedings be conducted fairly and that individuals receive notice and an opportunity to be heard.

Entrapment:A defense claiming that law enforcement officials induced the defendant to commit a crime they would not have otherwise committed.

Exculpatory Evidence:Evidence that tends to establish a defendant's innocence or reduce their culpability. Prosecutors are constitutionally required to disclose such evidence under Brady v. Maryland.

Felony:A serious criminal offense, typically punishable by imprisonment for more than one year, and often carrying additional collateral consequences.

Grand Jury:A body of citizens convened to evaluate evidence presented by the prosecution and determine whether there is probable cause to issue an indictment.

Habeas Corpus:A legal writ that requires authorities to bring a detained person before a court to determine whether the detention is lawful.

Indictment:A formal charge issued by a grand jury stating that there is sufficient evidence to bring a defendant to trial.

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