The purpose of the present review is to organize the theoretical approaches toward criminal acts and provide a structured source for the use of forensic researchers. The causes of criminal actions have been studied by different disciplines to decrease crime rates and understand the nature of criminal acts. ''Crime can be easily defined as any activity publicly proscribed by the written laws of a society'' (McGuire, 2004, p. 3). However crime is a complex issue, and that is why theorists have investigated the causes of criminal act using different perspectives and explanations. These explanations can be classified into three main categories as biological, psychological and sociological. Crime theories are also categorized based on their levels and scopes, and evaluated as five levels from large scale to individual factors; (i) societal macro level theories, (ii) community or locality level theories, (iii) group and socialization influence theories, (iv) crime events and routine activities, and (v) individual level theories. It is a fact all theories have a useful function in the literature, but they should be presented within an organized framework.
Keywords: crime, criminal act, crime theories, theoretical review, forensic research