The criminal justice industry deals with various aspects of processing criminals through the court system and monitoring their activities after they have served their court sentence, whether jail time or probation. Law enforcement entails policing and enforcing laws; many of the careers in the field entail investigating suspicious activities, gathering evidence and facts about crimes, and studying and analyzing criminal behavior and crime statistics. The criminal justice industry is also involved in providing structured guidance for criminals to help them improve their lives and curb certain behaviors, such as through rehabilitation programs and counseling for anger management or substance abuse.

The study of crime and punishment has roots in the 18th century. Before then, harsh punishment such as torture was meted out to criminals, and often the punishment was for petty infractions or even for people who were only suspected of committing crimes. Starting in the 1700s, society gave more consideration to crime, in an effort to better understand the reasons for the crime and what might be the best punishment for the crime. This period of thought and debate brought about the classical school of criminology, which theorized that people choose to commit crimes, and that the purpose of punishment should be to prevent future crime.

Today there are many different types of careers in the criminal justice field that focus on the study of crimes and criminal behavior. Some of these jobs include criminalists, criminologists, and sociologists. Criminalists may also be known as forensic science technicians or crime scene investigators. They collect and analyze evidence from crime scenes. They may specialize in crime scene investigation or laboratory analysis, and there are specialists within these fields such as forensic pathologists, latent print examiners, and digital forensics analysts, among others.

Sociologists who specialize in researching and analyz...