In this report, "exceptional circumstances" is understood in the context of definitions used by Finland's Defence Council and in the legislation on preparedness. According to these sources, war, the threat of war, an economic crisis, and a catastrophe lead to exceptional circumstances. This study also considers other crises that may have an impact on crime. These include revolutionary activity in connection with a serious political crisis, a rebellion, organized terrorism, and large-scale evacuations or uncontrolled migration that results from severe political crises or catastrophes. Crime patterns under exceptional circumstances generally show trends that relate to predatory survival behaviors, the erosion of moral values, and a reduction in the fear of punishment. The foundation for preparedness against criminality and for the prevention of crime in exceptional circumstances lies in the main dimensions of crime prevention: sociopolitical, society-based, and opportunity- centered crime prevention. Once an exceptional circumstance has occurred, an effort should be made to recapture control over the situation primarily through the means and organizations that exist during normal times and, only secondarily, through the special powers granted by emergency legislation. The exercise of special powers should be restrained so as not to endanger the legitimacy of society. In this exercise of special powers, all measures should be avoided that would be relatively detrimental to overall crisis management or to the process of restoring normal socioeconomic and political functioning. Infringements of human rights and abuse of power can be prevented through division of power and through workable democratic control, together with open communications.