An Examination of the Institutions of Investigation and Prosecution in Iranian Criminal Law and English Law

Preliminary investigations and prosecution are legal prerogatives of prosecutorial authorities and the police, functioning as human instruments in the procedural stages of criminal justice in both the Common Law system of England and the Romano-Germanic systems in France and Germany. Similarly, Iran—through a fusion of Islamic jurisprudence and codified law (Romano-Germanic)—has been influenced by both the substantive and procedural aspects of French criminal law. In England's criminal procedure, while observing the principles of fair trial, the police—rather than the public prosecutor's office—hold independent and lawful authority over crime detection and preliminary investigations. The Crown Prosecution Service (CPS) acts as the prosecuting body and is responsible for initiating prosecutions in court. However, in the Romano-Germanic legal systems and in Iran, which follows this model, the police are legally mandated—under the supervision and directives of the public prosecutor—to perform the lawful functions of crime detection and preliminary investigations in accordance with the Code of Criminal Procedure. English law recognizes one of its core prosecution principles as the discretionary authority to suspend prosecution, terminate prosecution, or accept guilt, which are seen as key manifestations of this principle. This principle is also embedded within Iran’s Code of Criminal Procedure. The present study investigates the institutions of investigation and prosecution in Iranian criminal law and English law.