ABSTRACT
Crimes against humanity and war crimes, committed there, in Rwanda and in several other places all over the world, as well as many other appearances of crimes, remind people daily that criminality on the domestic and international level is a social disease, the sources of which have to be researched and abolished, if prevention should reach its highest degree of effectiveness. Therefore, the challenge to impunity, heading their Conference in Trento, is a challenge to all people, and on every occasion. Prevention, deterrence and repression are, all three, rather complex concepts. It is the aim of criminal law to serve as ultima ratio for the protection of legally accepted values and interests. All concepts to "fight" criminality agree that the most effective way to achieve the aim is to prevent crimes from being committed at all. Whatever means are chosen, their effectiveness should be evaluated in advance, if possible by empirical research.
