Criminal law is a legal system concerned with punishment of individuals who commit crimes. Therefore, a criminal prosecution involves the government deciding whether to punish an individual for either an act or an omission–not the victim of a crime or the family of a victim of a crime.

Criminal Codes

In the USA, each state decides what conduct to designate a crime. Therefore, each state has its own criminal code. Congress  claimed the right to itself to punish certain conduct, codifying federal criminal law in Title 18 of the U.S. Code.

Codification of Criminal Procedure

Congress codified the federal criminal law and criminal procedure in Title 18 of the U.S. Code with §§ 1 to 2725 dealing with crimes. Title 18 designates certain conduct as federal crimes, including arson, counterfeit and forgery, embezzlement, espionage, genocide, kidnapping… These statutes usually prescribe a maximum sentence appropriate for the individual convicted of the crime.

The federal government codified the specific procedures to be used during the course of a criminal proceeding in the Federal Rules of Criminal Procedure.

Elements of a Crime

An individual commits a crime if they act a way that fulfills each element of a crime. The statute establishing the crime also establishes the elements of the crime. Generally, every crime consists of three elements:

  1. the act or conduct “actus reus”,
  2. the person’s mental state at the time of the act “mens rea”,
  3. the causation between the act and the effect–“proximate causation”. In a criminal prosecution, the government has the burden of proof to establish every element of a crime beyond a reasonable doubt.

Types of Crimes

Crimes are categorized in four categories: felonies, misdemeanors, inchoate offenses, and strict liability offenses.

Congress limited power to make criminal laws because such power is principally reserved to states.

Sentencing Guidelines

Federal courts use the Federal Sentencing Guidelines, whereas state courts consider state-specific sentencing guidelines.

Liability for Accomplices

When more than one party are involved in a crime, the first step is to classify the participants according to the following criterion:

Those who actually commit a crime (i.e. the perpetrator). Perpetrators are not accomplices and this section does not pertain to them.
Principal in the second degree – those who aided, counseled, commanded, or encouraged the perpetrator in the actual commission of a crime. An abettor is considered an accomplice.
Accessory before the fact – those who aided, counseled, commanded, or encouraged the perpetrator to commit the crime, without actually being present at the moment of perpetration. An accessory (before the fact) is considered an accomplice.
Accessory after the fact – those who aid an individual, knowing the individual to be a criminal, in an effort to hinder the individual’s detection, arrest, trial, or punishment. Accessories (after the fact) are guilty of a separate crime, so this section does not pertain to them.
To convict an accomplice, the prosecutor needs to establish the requisite actus reus and mens rea. That is, the prosecutor must prove that the accomplice acted in support of the perpetrator, and had the requisite mental state while doing so. It is important to note that some jurisdictions allow accomplices to be prosecuted independently of the principal perpetrator. Thus, an accomplice could be found guilty of a more severe offense than the principal. In certain jurisdictions, an accomplice may be convicted while the alleged perpetrator is acquitted.

Ex Post Facto

An ex post facto law retroactively punishes actions. The Constitution forbids this practices in Article 1, Sections 9 and 10.

Punishing For Status

The Supreme Court explained in Robinson v. California, 370 U.S. 660 (1962), any statute that criminalizes the status of a person inflicts a cruel and unusual punishment in violation of the Eighth Amendment and Fourteenth Amendment. For example, a state could not punish an individual for “being homeless,” which would be a status offense, but could punish a homeless individual for trespassing or loitering, which involves some action/event.


There are a number of defenses available to a defendant in a criminal prosecution including:

  • Failure of Proof
  • Mistakes
  • Mistake of Law
  • Mistake of Fact
  • Self-Defense
  • Defense of property
  • Defense of Others
  • Necessity
  • Excuses
  • Duress
  • Intoxication
  • Insanity



AA Editor

Written by Editor

Website: https://aboutlaw.com

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