The guide assumes that the law enforcement agency has already conducted a detailed problem analysis and is at the stage of exploring alternative responses, with one of those responses being the closing of streets or alleys. The report explains why street and alley closures might be expected to reduce crime or disorder, and it summarizes the literature on the effectiveness of this measure, followed by an outline of the arguments for and against this policy. A checklist of questions is provided to facilitate decisionmaking on the issue, and steps are suggested for implementing a decision to pursue this policy. Overall, the report notes that the police in some communities have reduced local crime problems by closing selected streets and alleys. This policy has been particularly effective in reducing street prostitution, gang activity, robbery, burglary, and drug-dealing; however, such closings do not always work, and they often engender opposition to the police in the affected neighborhood and nearby neighborhoods. Implementation of such a policy, therefore, requires considerable time and effort to acquaint residents and businesses with the rationale for the closings and the likely beneficial effects. Depending on public support for the closings and whether there is a consensus on the streets that will be closed, other options might be preferable. 25 notes, 38 references, and 17 annotated recommended readings