Surveys of public opinion conducted at different times in Canada and in the UK show that many more respondents believe in the criminal courts than in the police for controlling crime. The implications of this perceived gap in the crime control efficiency of punishing and of policing are examined through an analysis of the notions of penal justice and of security, considered as providing the theoretical underpinnings of two paradigms of crime control. These two concepts are discussed in terms of meaning, kinships, differences and the conflicts that their application may generate at the level of practice. It is concluded through the presentation of field experiments in the development of a new model of policing that justice and security may be complementary but their integration cannot be so complete as to abolish their difference.