A conceptual scheme for assessing and managing dangerous behavior has three major elements: assailants; targets; and settings, situations, and temporal factors. An assassination attempt cannot occur unless all three are in place, and even then it can be prevented. To accomplish its preventive mission, the Service should have advance information about the movement mission, the Service should have advance information about the movement of protected persons and some control over publicity. A review of previous assassination attempts reveals that targets almost never were attacked while in their regular or even temporary places of work, but were in some public setting. Since social values place limitations on firearms controls and surveillance measures, the Service theoretically should concentrate on greater control of targets and settings, situations, and temporal factors. It should also give some attention to identifying those persons who are of more critical protective interest and at great risk judging from past data on assassinations. One option would be providing funds for designated persons to obtain their own private protective services. To improve predictive accuracy of events with extremely low base rates, data could be gathered from assaults on State and local political leaders, other countries, the New York City Police, and other national leaders. In conclusion, the Service must increase its capacity for inhouse research, fund outside research efforts, establish a research advisory committee, and re-evaluate its organizational structure.