Prevention is divided into two areas.
Police Prevention is the heart of police work. It should prevent crime, including the prevention of success in case of criminal offences which are already underway - also minimize the consequences. Each individual measure of police work, even the mere presence is prevention. In this respect patrols, reconnaissance missions and technical measures such as technical surveillance of the border are part of prevention.
(Police) Crime Prevention
Crime prevention is the prevention of unlawful acts. Thereby one can distinguish between universal (i.e. primary or general), situational or selective (also secondary) and indicated (also: tertiary or post indicated), prevention as well as situational, offense-related and victim-related prevention. Primary and secondary prevention should prevent the initial-offense: tertiary prevention shall help prevent the recurrence. The terms primary, secondary and tertiary prevention are used for classification and should not be applied anymore because the modern criminology most likely understands the pattern of selective or indicated prevention as crime prevention. Crime prevention is the duty of the entire society. The contribution of the police in it is called "Police Crime Prevention".