Fundamentals and Criteria of Preventive Detention in German & Iran Law and Imamiyeh Jurisprudence

Punishments are changeable and depend on goals. Therefore, when there is valid knowledge that correctional goals of punishment are failed, releasing a criminal who certainly endangers public safety is a denial of public rights. In this case, presumption of innocence has been changed to presumption of guilt and the judge by realizing the objective and qualitative criteria that indicate the survival of dangerous situation, can determine the preventive detention.Therefore, with qualitative approach and phenomenological methodology through library studies, this article seeks to address the following question: "What are the principles and criteria for legislation of preventive detention in the German, Iran and Imamiyeh jurisprudence legal system?"The findings are that the main bases of preventive imprisonment are the discourse of overcoming public security over freedom, the discourse of victim-centered criminal law, the principle of caution and the rule of the need to repel harm, but the problem is the criteria for achieving a valid suspicion of a dangerous situation. It seems that valid suspicion can be obtained by determining quantitative and qualitative criteria.Iranian legislature, relying on reasonable grounds and criteria, in cases of valid suspicion of a dangerous situation can legislate prevent imprisonment for dangerous criminals.