The problem chosen for the feasibility study was vandalism in schools in an area of Manchester, England. The Working Group had devised a simple decisionmaking procedure that could be applied to any offense, although in practice it might be best applied to narrowly defined offenses. The procedure involves a thorough analysis of the situation in which the offense occurs in order to establish the prerequisite conditions (opportunities, motivation, and legislation) for the offense to be committed; the identification of measures which would make it more difficult or impossible to fulfill each of these conditions; an assessment of the practicality, likely effectiveness, and costs of each of these measures; and the selection of the most promising measures. The feasibility study of vandalism in Manchester was developed in three stages: discussions with local government officers, local police, other interested parties, visits to schools, and detailed analysis of vandalism records, in order to find suitable schools to participate in the project; a research and planning phase in which 11 schools were invited to take part; and a decisionmaking and implementation phase, which involved the convening of a meeting for each of the schools to discuss preventive measures. The project was primarily concerned with how more effective preventive strategies might be developed rather than with the particular problem of vandalism. In presenting this case study, the intention is to make a contribution to the general debate on crime prevention by illustrating some of the obstacles to effective decisionmaking. Footnotes and about 35 references are included. A guide for preventing school vandalism, an essay on the availability of information, and information on glass substitutes are appended, along with a list of Home Office publications.