This chapter discusses various theories of criminology and crime statistics reporting in the United States. It introduces biological, psychological, and sociological explanations for criminal behavior. Sociological theories covered include social disorganization theory, differential association theory, and strain theory. The chapter also discusses conflict theories. It describes the development of victims' rights advocacy and the role of the Uniform Crime Report, National Incident-Based Reporting System, and National Crime Victimization Survey in collecting and reporting crime statistics in the US.