Uniform crime reports - published by the fbi, lists the number of crimes reported since not everyone reports it, does not include all crimes do not include drug related offenses, only serious street crimes. Self report surveys - people are asked to report how many offenses they have committed majority of people have committed crimes. Cesare lombroso - biological traits crime is predetermined. Thinking and decision making of offenders - rational choice theory - relates to opportunity theory, and perceptual deterrence theory biosocial perspective - research on brain, genetics & other biological factors. Criminal man - a search for biological traits that differentiate offenders from non offenders life course/developmental criminology - roots of crime related back to childhood. The search of explanations of criminal behaviour is not easy because we constantly must guard against our biases, mistaken perceptions, and prejudices. Consists of perceptions and interpretations of the past as well as the present.