The oldest known codified law is the Code of Ur-Nammu, written in the Sumerian language circa 2100 BC-2050 BC. The preface directly credits the laws to king Ur-Nammu of Ur. In different parts of the world, law could be established by philosophers or religion. In the modern world, laws are typically created and enforced by governments. These codified laws may coexist with or contradict other forms of social control, such as religious proscriptions, professional rules and ethics, or the cultural mores and customs of a society.
Within the realm of codified law, there are generally two forms of law that the courts are concerned with. Civil laws are rules and regulations which govern transactions and grievances between individual citizens. Criminal law is concerned with actions which are dangerous or harmful to society as a whole, in which prosecution is pursued not by an individual but rather by the state. The purpose of criminal law is to provide the specific definition of what constitutes a crime and to prescribe punishments for committing such a crime. No criminal law can be valid unless it includes both of these factors. The subject of criminal justice is, of course, primarily concerned with the enforcement of criminal law.
 Criminal justice system
The criminal justice system consists of three main parts: (1) Legislative (create laws); (2) adjudication (courts); and (3) corrections (jails, prisons, probation and parole). In the criminal justice system, these distinct agencies operate together both under the rule of law and as the principal means of maintaining the rule of law within society.
Main article: Police
The first contact an offender has with the criminal justice system is usually with the police (or law enforcement) who investigate the suspected wrongdoing and make an arrest, but if the suspect is dangerous to the whole nation, a national level law enforcement agency is called in . When warranted, law enforcement agencies or police officers are empowered to use force and other forms of legal coercion and means to effect public and social order. The term is most commonly associated with police departments of a state that are authorized to exercise the police power of that state within a defined legal or territorial area of responsibility. The word comes from the Latin politia ("civil administration"), which itself derives from the Ancient Greek πόλις, for polis ("city"). The first police force comparable to the present-day police was established in 1667 under King Louis XIV in France, although modern police usually trace their origins to the 1800 establishment of the Marine Police in London, the Glasgow Police, and the Napoleonic police of Paris.
Police are primarily concerned with keeping the peace and enforcing criminal law based on their particular mission and jurisdiction. Formed in 1908 the Federal Bureau of Investigation began as an entity which could investigate and enforce specific federal laws as an investigative and "law enforcement agency" in the United States; this, however, has constituted only a small portion of overall policing activity. Policing has included an array of activities in different contexts, but the predominant ones are concerned with order maintenance and the provision of services.
Main article: Courts of Law
The courts serve as the venue where disputes are then settled and justice is administered. With regard to criminal justice, there are a number of critical people in any court setting. These critical people are referred to as the courtroom work group and include both professional and non professional individuals. These include the judge, prosecutor, and the defense attorney. The judge, or magistrate, is...