During the criminal justice process, we have investigation, prosecution, and adjudication these steps, and the trial is included in adjudication. So we can see Investigation and trial are two quite different process during the criminal justice, and they have two quite different use. During this paper the writer will introduce the define and how to work of them.

As in France  and Spain , or on the state’s attorney, as in West Germany , investigation is in all procedural systems a function of the police as well as the law often confers investigatory authority on a magistrate in criminal matters. These officials regularly delegate routine matters to police or other nonlegal personnel but retain the right to investigate important or sensitive cases. Express judicial authorization of acts interfering with the liberty or privacy of citizens is required in all systems, but exceptions for urgent cases are provided with carrying liberality.

Pretrial detention can be ordered only by a magistrate . No judicial warrant is necessary, however, for arrest and brief detention by the police if the suspect is apprehended while committing the crime or shortly thereafter, or under circumstances creating strong suspicion. In West Germany, the police can arrest and detain a sus英语论文网 【http://www.51lunwen.org】pect for up to forty-eight hours if there is good reason to believe that he might flee or destroy evidence. Searches and seizures must on principle be ordered by a magistrate, but they can be conducted without such authorization if required by exigent circumstances . Standards of suspicion authorizing police to conduct searches and to make arrests tend to be somewhat lower in civil law countries than the exacting probable cause requirement imposed by American law. Because the law accords the individual less extensive protection against invasions of his privacy in the course of a criminal investigation, and everywhere citizens need protection from overzealous police. The conflict between law enforcement and the individual’s privacy does not lend itself to simple solutions, since both interests are valued highly in free societies. American law has adopted an indirect approach designed to give maximum protection to the individual. Evidence obtained in violation of the suspect’s rights cannot be used in court to support a conviction . Proponents of that rule, assuming that police have a professional interest in the conviction of criminals, expect it to have a deterrent effect on illegal police behavior. In other systems, comparable but less sweeping rules apply. Because indirect control of the police through the exclusion of tainted evidence is severely limited in civil law countries, one would expect to find other control mechanisms. Such alternatives exist, but their practical 本文来自：英语论文网 【http://www.51lunwen.org】