Police know that the way in which living environments are designed plays a role in determining the rate and type of criminal activities in a community. Other public officials, however, have been slow to recognize that crime prevention is an integral part of urban planning. Environmental security planning promotes the concept of "defensible space," whereby the design of a living environment enables residents of an area to view the activities of people in public areas, including criminal activities. Experienced police officers can identify high-risk neighborhoods by identifying potential crime targets. They can emphasize the importance of adequate lighting at night and the elimination of places of concealment. Any matter coming before a planning commission that involves change to the overall community plan should include input from other local government agencies. At this stage, the police agency should have the opportunity to provide its expert advice regarding safety and security issues in planning decisions. Some researchers have suggested that police agencies with 75 or more personnel should have at least 1 person assigned to full-time planning responsibilities. In smaller agencies, personnel with particular expertise in crime prevention should be assigned the planning responsibility.