Preventing crime is regarded as one of police`s most important duties in IRI. Police`s duties of social order, security, personal and public pacification would be performed only if special attention be paid to prevention of crime. There can be found different policies in different systems of laws for prevention of crime studying them in comparison with what found in Malek`s pact an extraordinary distinction would be made clear. Considerable particularity of Malek`s pact includes three levels of commanders` duties towards those under command and good behavior these forces should have towards people. In this way, the pact implied most applicable effect in police prevention of crime. The paper, on this basis, seeks to present a method for preventing crime.