The Code of Criminal Procedure, 1973 is the procedural law providing the machinery for punishment of offenders under substantive criminal law. The code contains elaborate details about the procedure to be followed in every investigation, inquiry and trial, for every offence under the IPC or any other law. Earlier there was no uniform law of criminal procedure until Criminal Procedure Code of 1882; it was replaced by the Code of 1898. The act was amended in 1923 and 1955. This code was repealed by the Code of 1973 enacted by Parliament on 25th January, 1974 and made effective from 1-04-1974 so as to consolidate and amend the law relating to Criminal Procedure.  Its object is to provide a machinery for determining the guilt of and imposing punishment on offenders under the substantive criminal law, for example, the Indian Penal Code (I.P.C.). The two Codes are to be read together. The Code also provides machinery for punishment of offences under other Acts.

The substantive laws like IPC need a mechanism to be implemented and this mechanism was created and named as the criminal procedure code, 1983. In order for the substantive laws to come into operation, procedural law is imperative. So, procedural and substantive laws are supplementary to each other.

The purpose behind drafting CrPC was to ensure that the accused and the victim get equal opportunity to a fair trial. The purpose of drafting the code can be fulfilled if each and every provision of the code passed the test of a) simplicity b) expediency c) affordability.

The code is consolidating and amending. It mentions the procedure of applying substantive law but in case any special law already exists where the procedure for such law is already mentioned, then that law would be given precedence over it. It is deemed to be exhaustive but if any subject is not mentioned in the CrPC then the court is empowered to frame laws on the same. Any claim under the code will lie only after the code came in existence i.e. 1973.

The code has shelled out responsibility to different sections of the society for administering the right procedure. The process starts with the role of the common people to feed the police with the information of occurrence of any crime. The responsibility shifts to the police when it undertakes the next step of investigation. It spans from knowing about the crime to filing the charge sheet. After this come the role of the magistrate where inquiry follows investigation. If the inquiry convinces the magistrate of the charge, then it leads to trial. Trial lends the justice delivery system in the hands of prosecutors and conviction or acquittal leaves it in the hands of prison authorities and the common people again. So, the code has provision to regulate all these five steps involved in enforcement of the substantive law.

The code is complete code with respect to matters provided under it, thus the code must be deemed to be exhaustive. The Supreme Court has said “It is the procedure that spells much of the difference between the rule of law and the rule of whim and caprice”. (Iqbal v. State of Maharashtra (1975) 3 SCC 140)