The paper first portrays the so-called "justice gap" in the world, which refers to the fact that large numbers of people in the world have no access to the instruments of justice, so they have no recourse if they are victimized. The author, who has been head of research in the United Nations International Drug Control Program, then explains why an international institution such as the United Nations has a comparative advantage in efforts to close the "justice gap." Four lessons learned by the author in his research are then outlined. First, measure the central crime phenomena; count them when possible; keep counting them; and make quality improvements gradually and incrementally over time. Second, publish the information obtained from sound research, so the public will not, by default, be only exposed to the media's selective, dramatic, and frightening information about crime. Third, present the concepts of terrorism and drug trafficking in terms of their actual impact, i.e., number of civilian casualties and drug production volumes and prices, and use these data to develop an empirical base for policy. Fourth, make research relevant to policy and integrate it into policy development. The paper concludes with a discussion of how these lessons can be applied in related areas and be used in models of good practice for crime research. 1 figure and 9 references