Why do people commit crimes? This 20-slide PowerPoint traces the historical roots of criminology starting with Classical Theory of the 17th century, Positivism of the 19th century, and concluding with modern biological, psychological, and sociological theories. Each slide contains a lot of information and teachers may wish to spread this presentation over several days. This presentation was originally created for a grade 12 law class but could be used in an introductory college-level course in criminology. Download the free preview to see 5 of the slides.