Frankfurt am Main has the highest crime rate of any city in West Germany. The character of the city is influenced by its position as the main economic and cultural center for a wide area, with a large number of commuters, foreigners, tourists, foreign armed forces, major exhibitions and fairs, banks, and the major airport in West Germany. These diverse activities provide fertile ground for crimes such as drug trade, prostitution, and street offenses. Frankfurt has also been a major center of terrorist activities. Because of this complex criminal and population structure, the police must enforce the law selectively. Critics complain that the selective criteria are class-related, but in fact they depend on what crimes are reported and on police officers' knowledge of where particular types of criminals are likely to hide out. Police usually concentrate on particular types of crimes and groups of criminals: for example, more resources are likely to be expended in investigating murders than shoplifting. Without such selection police would be unable to function with their available resources. An Information and Evaluation Unit has existed since 1977. The purpose of the unit is to gather information on crime centers and offense contexts. The system produces daily and monthly reports of street crimes. To improve emergency search procedures in Frankfurt, an atlas containing maps of all patrol areas has been developed. When a manhunt alarm is sounded, checkpoints are manned in each area to coordinate the search. A further systematic approach to combating crime would focus on gathering information about offenders' characteristics rather than on collecting information about the offenses alone. Types of offenders could then be linked to particular kinds of crimes. Tables are supplied.