Radical criminology states that society "functions" in terms of the general interests of the ruling class rather than "society as a whole" and that while the potential for conflict is always present, it is continually neutralised by the power of a ruling class. Radical criminology is related to critical and conflict criminology in its focus on class struggle and its basis in Marxism. Radical criminologists consider crime to be a tool used by the ruling class. Laws are put into place by the elite and are then used to serve their interests at the peril of the lower classes. These laws regulate opposition to the elite and keep them in power.

Given its nature, radical criminology is not well funded by governments and is generally not supported by government policies. Some argue that the radical criminological perspective has waned in influence, particularly with an aging population. Concerns about its credibility and utility persist, and there is ongoing debate about whether radical criminology still exists.

Radical criminology is based on a variant of Marxism called Instrumental Marxism. It rose in popularity in the US in the 1960s amid the Civil Rights and Anti-War movements. The protests of students and minorities caused sociologists and criminologists to look to situational explanations of social and political unrest in America. Radical criminology's popularisation coincided with the rise of conflict and critical perspectives. All three share a common basis in Marxist ideals. In 1990 the Division of Critical Criminology was recognised by the American Society of Criminology, which solidified radical criminology as a legit theory. The band Rage Against the Machine as an example of the radical perspective.

Radical criminology posits that the current criminal justice system seeks only to serve the interests of the ruling class and thus perpetuates inequality in society. The justice system creates white collar, high class jobs while alienating oppressed minorities from the job market. The justice system’s fixation on repeat offenders and punishment reflects an adherence to individual blame theories that alleviate the blame on those in power. This is seen through the focus on street crime rather than white collar crime.

Radical criminologists reject the legalistic definition of crime for one centered in the violations of human rights. This includes the crimes committed by the ruling class such as pollution and exploitation that are not typically considered crimes. Radical criminologists also reject all individualistic theories of crime such as biological and psychological in favor of analyzing the social conditions that cause individuals to be labeled as criminals. Radical criminologists see mainstream theories of crime and deviance as serving to uphold the status quo of capitalism. The only way to solve the crime problem is to overthrow the capitalism system from which the conflict originates.

Radical criminologists are abolitionist in that they seek to end all state criminal justice systems that cause the suffering of the oppressed.

Radical criminologists believe that traditional criminology puts too much emphasis on the violence of property crime. Property crime is a symptom of a system that exploits the lower classes and puts the well-being of the property of the upper class above the needs of the lower class. Therefore it is not truly a crime, but only a reaction to an unjust society. Under capitalism, all crimes committed by the lower class are necessary for their survival.

Radical criminologists reject the ideas of national sovereignty and border security. These exist because of the state's oppression and should be challenged. Therefore, no immigration should be illegal.