In order to prevent any sexual assault from occurring again, such criminal restrictions as the probation system, the community service order, the probation office order, the personal information disclosure, the electronic monitoring system for the positioning of sex offenders, and the anti-sexual drug treatment are currently being applied. However, in order to make such restrictions become more effective in our society, it is necessary to ensure the internal stability of such restrictions first of all. Also, it is important to consider the potential disputes which could be caused by the problems related to such factors as legality, the violation of human rights, the application of dual punishments, the prohibition of excessive punishments and the retroactive prohibition. Furthermore, since the preventive custody for sex offenders in terms of medical treatment and protection can also be regarded as the measure for the deprivation of their freedom beyond the limitation given by the responsible criminal law, a pressure for justification is being given in terms of the constitutional aspect. In terms of the institution and the system, many people will definitely believe that it is possible to completely remove all the sexual assaults from our society. However, by closely looking at the process of combining all the institutions, they will become suspicious of the justification of the complicated criminal restrictions in terms of the quantitative and qualitative aspects based on the absence of clear fundamental solutions to prevent any sexual assault from occurring again. Therefore,it can be said that the problem is not about the addition of any other institution or system, but about the identification of the target for the application of such an institution or system. Since objectives do not justify means, it is important to carefully consider the proper criminal and social policies required for the application of suitable criminal restrictions to the criminals who might commit sexual assaults again through the aspect of a constitutional state within the constitutional limitation.