Criminal justice is the application or study of laws regarding criminal behavior. Those who study criminal justice include the police, those working in a judiciary capacity, and lawyers who either defend or prosecute those accused of a crime. Others work to advocate for changes in the current system of criminal justice, such as those who render decisions regarding current laws, like members of Supreme Courts. It is important that the criminal justice system includes the word justice, since laws applied to those accused of a crime should be fair.

As a field of study, most who will work with parts of the law that involve behavior defined as criminal, will study criminal justice. Training and certification for police officers often is merely called criminal justice. Lawyers with a special interest in either the prosecution or defense of suspected criminals may also choose to major in criminal justice in a four-year degree program. Knowledge of the laws, rights and privileges of victims and suspects is essential to aiming for justice in both the court and law enforcement systems.

Those who have interest in training with the FBI or CIA may also choose to obtain a four-year degree in criminal justice. Such a degree not only studies the law as it stands, but as well evaluates the law. Subjects in universities that offer a major in criminal justice may be varied. They may include topics like forensic psychology, history of criminal justice, ethics, and sociology.

There are colleges where students pursuing law can attend part time classes. Night classes are also arranged for law students. So it all depends on the students as to which course he is willing to go for.