Does allowing people to own or carry guns deter violent crime? This text aims to present a comprehensive data analysis, and comes to the conclusion that more guns means less crime. The book uses a wide range of sources, including the FBI's yearly crime figures for all US counties, national surveys on gun ownership and police documentation on illegal gun use. The unexpected findings suggest that many of the commonly-held assumptions about gun control are incorrect. The author maintains that criminals generally respond to deterrents - as the risk and potential cost of crime rises, criminals commit fewer crimes.