Criminal justice is the delivery of justice to those who having committed crimes. The criminal justice system is a series of government agencies and institutions whose goal is to identify and catch the law-breakers and to inflict a form of punishment on them. Other goals include the rehabilitation of offenders, preventing other crimes, and moral support for victims. The primary institutions of the criminal justice system are the police, prosecution and defense lawyers, the courts and prisons.
Criminology (from Latin crīmen, "accusation" originally derived from the Ancient Greek verb "krino" "κρίνω", and Ancient Greek -λογία, -logy|-logia, from "logos" meaning: “word,” “reason,” or “plan”) is the scientific study of the nature, extent, management, causes, control, consequences, and prevention of criminal behavior, both on the individual and social levels. Criminology is an interdisciplinary field in both the behavioral and social sciences, drawing especially upon the research of sociologists, psychologists, philosophers, psychiatrists, biologists, social anthropologists, as well as scholars of law.
Justice is the legal or philosophical theory by which fairness is administered. The concept of justice differs in every culture. An early theory of justice was set out by the Ancient Greek philosopher Plato in his work The Republic. Advocates of divine command theory say that justice issues from God. In the 17th century, theorists like John Locke advocated natural rights as a derivative of justice. Thinkers in the social contract tradition state that justice is derived from the mutual agreement of everyone concerned. In the 19th century, utilitarian thinkers including John Stuart Mill said that justice is what has the best consequences. Theories of distributive justice concern what is distributed, between whom they are to be distributed, and what is the proper distribution. Egalitarians state that justice can only exist within the coordinates of equality. John Rawls used a theory of social contract to show that justice, and especially distributive justice, is a form of fairness. Property rights theorists (like Robert Nozick) take a deontological view of distributive justice and state that property rights-based justice maximizes the overall wealth of an economic system. Theories of retributive justice are concerned with punishment for wrongdoing. Restorative justice (also sometimes called "reparative justice") is an approach to justice that focuses on restoring what is good, and necessarily focuses on the needs of victims and offenders.
Liberty, equality — bad principles! The only true principle for humanity is justice; and justice to the feeble becomes necessarily protection or kindness.
Henri-Frédéric Amiel, undated entry of December 1863 or early 1864, in Amiel's Journal : The Journal Intime of Henri-Frédéric Amiel as translated by Humphry Ward (1893), p. 215.