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Components of the US Criminal Justice System

Law Enforcement, Courts and Corrections in the US Justice System

The United States criminal justice system is broken down into three different parts, each with a different focus of the law and dealing with criminals in a different stage of their criminal activity. If you are currently in a criminal justice career, or are looking to enter the field, having a basic understanding of these three aspects of the justice system is essential.

When you’re tasked with the charge: Define Criminal Justice Systems, according to US standards – We urge you to use the information that follows.

3 Parts of the US Criminal Justice System - Explained


Law Enforcement in the American Justice System

The first component of the criminal justice system is law enforcement. Individuals in this component include patrol officers, sheriffs and deputies, federal agents, game and parks rangers, detectives and other individuals that usually make first contact with criminals. These individuals are responsible for upholding the law, investigating crime and apprehending the individuals responsible for committing the crime.

Law enforcement individuals must be knowledgeable of the individual rights of suspected offenders such as Miranda rights, search and seizure rights and reasonable stops to name a few. Officers also need to be aware of citizens’ and civil rights so as not to violate those rights or compromise an investigation if a crime was indeed committed.

The Courts in the American Justice System

The second component of the criminal justice system is the courts. When you ask, “How does the criminal justice system work?” the courts are one of the essential pieces of the puzzle. Key individuals in play in this component of the US justice system include judges, prosecutors, defense lawyers and jury members. Many of these positions are held by elected officials such as county and district attorneys and judges.

Defense attorneys are generally private practice attorneys who specialize in certain areas of the law, such as family law or drug law, and are hired by a defendant. Public defenders are defense attorneys who are appointed to individuals who cannot afford an attorney. These defenders are either appointed from a public defender office or are part of a rotating pro bono requirement from the court. For example, in some family law courts, the public defenders are private attorneys in the area who are regularly hired by clients but will rotate taking case pro bono for clients who need a court-appointed attorney.

Jury members are selected from the pool of registered voters in a court’s jurisdiction and then further selected into a group of 6-12 members by the attorneys involved in the case before a trial begins. This position is minimally compensated but is a part of citizen responsibilities.

The individuals in the court component work to ensure an individual’s rights are not violated and a fair trial takes place. Juries and judges play a part in sentencing individuals for crimes committed, but they must each follow guidelines established by state and federal statutes.

Corrections in the American Justice System

The third component of the American criminal justice system is corrections. The corrections component includes probation officers, parole officers and corrections officers. These individuals ensure that a convicted offender serves his or her sentence as advised by the courts and supervises the convicts as they service their sentences.

Corrections officers supervise inmates that are being housed and serving sentences in prison. Corrections officers can also be found in county and city jails where inmates serve sentences for misdemeanors or being detained before or during trial.

Probation officers supervise adult and juvenile offenders who are being monitored by the courts in lieu of serving a sentence in jail. Probation officers also conduct presentence investigations for the courts, giving recommendations for sentencing to a judge with compilation of information. Presentence investigations involved gathering criminal history, interviews of friends, family and colleagues of the convicted and offering a recommendation of sentencing to the court. They also continually report progress of the probationer to the courts and make recommendations of possible revocation.

Parole officers provide supervision of individuals released from prison early on parole, conducting home visits, drug tests and enforcing adherence of parole terms, also making recommendations of revocation when terms are broken.

Each of these three aspects of the criminal justice system is essential to the effective functioning of the larger system as a whole.

If you are interested in learning more about professions within the courts, law enforcement or corrections, you can find detailed explanations of each on our program pages.

You can also learn more about what type of education is needed to secure a position in the different arms of the criminal justice system by exploring more. An education is one of the most important aspects of making sure that the justice system is equitable and efficient.

Take some time to reach out to the criminal justice schools above if you’re ready to learn more.