The Commonwealth of Virginia has adopted a series of new provisions, scheduled to become effective, July 1, 1997. These provisions will provide directives for the criminal legal system in response to the issue of domestic violence. One of these provisions, the mandatory arrest of the "primary physical aggressor" in instances of assault and battery of a family or household member, is a matter of some controversy in Virginia and the nation. This article focuses on evaluating the effectiveness of the mandatory arrest provision in Virginia. The underlying premise of this article is that systematic evidence is different from personal experience, and even professional expertise, and that, in many situations, where systematic evidence exists, it is to be preferred over personal experience and professional expertise. This article suggests that the critical skills and faculties necessary to assess effectiveness in a systematic manner are lacking in the written records on the adoption of mandatory arrest in Virginia. Furthermore, there appears to be no commitment of resources on the part of the Commonwealth of Virginia to collect the systematic evidence necessary to assess whether its new reforms will, in fact, improve the safety of women. This article reviews the origins of the mandatory arrest provisions in Virginia, the logic and evidence presented in its support, and the available scientific evidence about the effectiveness of mandatory arrest as a means to prevent additional harm to the victims of domestic violence. The history of recent reforms in the criminal law relating to domestic violence measure effectiveness in terms of protecting the victims of domestic violence from subsequent harm. If, in fact, the safety of the victims of domestic violence is the goal of the new legal provisions in Virginia, the issues at hand are 1) the extent to which mandatory arrest has accomplished that goal in other jurisdictions and 2) how the citizens of Virginia will know if mandatory arrest has been effective in Virginia.