Introduction to US Criminal Justice System

By | August 4, 2021
Introduction to US Criminal Justice System

This article on, “Introduction to US Criminal Justice System” by Antariksh Anant focuses on what elements make up crime in the US and the classification of crimes and punishment exclusively in the country of the United States of America.

No nation can ever be perfect. There are bound to be some deviant activities. But not all deviant activity can be called a crime. Then how do we define crime, what are the essential elements which make an act a crime? How does the criminal trial proceeds? Who has the burden of proof and how high it is? These questions are significant in understanding the Criminal Justice system of any country.

This article will also discuss the features of criminal prosecution, which is completely different from civil litigations. Mostly we associate crime with harm to the victim, but that may not be the case always. Subsequently, it will be discussed with examples.

Introduction to US Criminal Justice System

Every nation has a criminal justice system which regulates the crimes, their essential elements, procedures, punishments, etc. This article will introduce the legal system of the US focussing on its essentials of crimes, punishments, burden of proof needed and other such relevant things.

Mostly, criminal law involves government attorneys, witnesses, evidence, etc. All these together have to follow the norms laid down in the procedure of trial for the judge to decide who is guilty. Thereafter, punishment is awarded based on the crime done.

Moreover, criminal prosecutions are initiated by the government attorneys, unlike the civil litigations where the plaintiff initiates. But before delving into all these technicalities, it is important to know what crime is and what the criminal justice system in the US is like.

Crime and Criminal Prosecution

Black’s law dictionary defines crime as “a positive or negative act in violation of penal law; an offense against the state.”[1] It even says “crimes are the wrongs which the government notice as injuries to the public and punishes what is called criminal proceedings.”[2]

The most basic definition of crime is ‘commission of any act which is in violation of law or omission of any act which was legal duty.’

Throughout the US, laws differ significantly from one state to another. Further, it may differ at the Federal and State level. This makes it a plethora of laws and an assiduous task to know all of them. These differences in law exist due to the cultural setup, geographic variety, and demographic qualities.

Moreover, laws are not static, they change with changing times. To maintain stability, it becomes essential that laws evolve with time. Criminal law talks about the rights and obligations of individuals in society while criminal procedure concerns about enforcement of an individual’s rights during the process.

The criminal prosecution begins after any federal or state criminal statute is violated. The parties are the government of the United States and the defendants or accused. If it is a federal criminal violation, then the government is represented by a US law attorney.

Whereas, in a state criminal prosecution, the representative is a state prosecutor. The criminal prosecution aims at punishing the wrong-doer for the wrong done. For this, the elements of the crime concerned need to be proved. Each crime has specific elements, but all of them have some general elements too. Such elements will be explained subsequently.

Elements of Crime

Crimes have been broken down into several elements. Every crime has to have three elementscriminal act (actus reus), criminal intent (mens rea) and concurrence of the two. Additionally, if there is any bad result in crime, elements of causation and harm also need to be proved.

The criminal act must have been done voluntarily. The code specifies involuntary acts as those done under hypnosis, sleep, unconsciousness, etc. Actus reus does not always have to be a commission of any act. It can be an omission too.

There are basically three situations where omission classifies as a crime:

  1. When there is any statute that creates a legal duty to act. Like filing tax returns is a legal duty created by respective statutes. Moreover, Minnesota Good Samaritan law makes it a duty to assist any person who is exposed to harm.
  2. When any contract creates any duty to act. Like a doctor’s contractual responsibility to treat the patient.
  3. When any special relationship exists, by virtue of which there is a legal duty born. Like parent’s obligation to provide basic amenities to their children.

All these elements of crimes are very different from what happens in civil litigation. The table below will point out the basic difference between them.

Ground of Difference Criminal Prosecution Civil Litigation
Victim Not always Yes
Harm Not always yes
Initiator of lawsuit State or federal government Plaintiff
Attorneys for initiator US attorney or state prosecutor Private Attorney
Attorneys for defendant Private attorney Private attorney
Goal Punishment Compensate the victim for the loss

How Can Crime be Harmless and Victimless?

Let’s take an example, John was angry at his friend Mike. So, he took his gun which had a silencer attached to it. He places it on his car seat and starts to drive. On his way, he had crossed the speed limits few times but did not hit anyone. Then he reached his friend’s house and hid behind the bushes.

He was waiting for his friend to come out of the house so that he can shoot him. When his friend came out, he shot thrice but the bullet missed his friend Mike. Mike was saved. But he can still be said to have committed crimes.

  1. If he does not have a license, it is illegal for him to keep a gun.
  2. He needs a permit to use a gun. In absence of it, he can be punished.
  3. Moreover, he attempted to shoot Mike, though Mike was not hurt, he can still be prosecuted.

In this way, crime does not always need a victim and necessarily fulfilling the harm done principle.

What if Defendant is Indigent Person?

The answer to this question can be found in the case of Alabama v. Shelton[3]. In this, Shelton was self-representing in the Alabama Circuit Court trial. He was at no time provided with counsel at state expense. He was convicted, then he appealed on the basis of the 6th Amendment to the US Constitution.

The court reversed the statement and further added that an indigent defendant in a criminal prosecution can be represented by a private attorney for free, wherein the government will pay for it. This is to be done because the 6th Amendment to US Constitution[4] provides for assistance of counsel.

Crime And Punishment

Crimes can be classified in different ways like based on subject matter or severity of harm done etc. The more substantive classification is on the basis of severity of harm done and thereby punishments are decided. The higher the severity, the greater is the punishment. This system of classification is called punishment grading.

Therefore, in the US there are four categories of crime and in the decreasing order of their severity, as follows:

  1. Felonies
  2. Misdemeanour
  3. Felony- misdemeanour
  4. Infractions

Felonies are the most serious crimes, accompanied by heinous intent, and severe consequences like loss of life, grievous injury, etc. As they are the most serious crimes, therefore their punishments are also more than others. Punishment for felony includes execution, prison time, fines, or alternative sentences like rehabilitation.

The second serious crimes are misdemeanours. The intent required is much less than the felony and hence the result is less serious. Punishments include jail time, fines, or alternative sentences like rehabilitation.

The third is felony misdemeanours. As the name suggests for itself, it is a mixture of the aforementioned two categories of crime. In other words, these crimes can be prosecuted as a felony as well as a misdemeanour. It absolutely depends on the circumstances and thereafter, on the judge’s discretion. Depending on the prosecution, the punishments given are either felony or misdemeanour.

The fourth and least serious crimes are infractions. In simpler terms infractions are violations. These are generally punishable by fines.

Another thing worth mentioning is the difference between prison and jail. Jails are operated by cities or counties, while prisons are operated by state or federal governments. The second point of difference is based on restrictive nature. Jails are less restrictive in nature than prisons, jails are for such wrong-doers who have committed less serious crimes.

Burden of Proof

The success of the parties in any criminal trial depends on the burden of proof. It is the responsibility (of party to the trial) to prove any disputed charge, allegation, or defence. It is made up of two different elements. They are burden of production and burden of persuasion.

The burden of production is to present the evidence before the judge while the burden of persuasion is the duty to convince the judge in a criminal trial. It is the duty of the prosecutor to prove the elements of the crime done. The burden of proof in criminal cases is always higher and it is beyond reasonable doubt.

In Commonwealth v. Webster, Chief Justice Shaw stated that:

“ what is reasonable doubt? It is a term often used, probably pretty well understood, but not easily defined. It is not mere possible doubt, because everything relating to human affairs and depending on moral evidence is open to some possible or imaginary doubts.

It is that state of case, which after the entire comparison and consideration of all evidence, leaves the minds of juror in that condition that they cannot say they feel an abiding conviction to a moral certainty; of the truth of the charge.”[5]

The prosecution’s evidence should be such that it overcomes the defendant’s presumption of innocence. Even if an inch of doubt remains then the defendant is presumed innocent, the case most likely lacks convincing evidence, hence the accused should be acquitted.

US law identifies two different tools to meet the burden of proof. They are inference and presumption. Also, evidence plays a crucial role.


Crimes are wrongful acts done voluntarily. US law identifies the three elements. They are actus reus, mens rea and concurrence of both. These are basic elements which every crime has to have. Additionally, each crime has specific elements. For a successful trial, the burden of proof is beyond any reasonable doubt.

There is a presumption that the accused is innocent and the prosecution needs to prove the accused guilty beyond a reasonable doubt. Moreover, crimes have been classified based on their severity and with every separate classification, the punishments also differ. The higher the severity, greater the punishment given.


[1] Black’s Law Dictionary (4th ed. 1968)

[2] Black’s Law Dictionary (4th ed. 1968)

[3] Alabama v. Shelton, 535 U.S. 654 (2002)

[4] U.S. CONST. Amend. VI

[5] Commonwealth v. Webster, 59 Mass. 295 (1850)

  1. Law Library: Notes and Study Material for LLB, LLM, Judiciary and Entrance Exams
  2. Legal Bites Academy – Ultimate Test Prep Destination

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