There is a rational basis for banning assault weapons as they are a firearm of choice among criminals. In a study of young adult purchases of handguns in California buyers with minor criminal histories were twice as likely to purchase automatic pistols as those with no criminal history. This was even higher at five times as likely for those who had been charged with two or more serious violent offenses. [1] This means those purchasing assault weapons intend for them to be used for violent ends.  It is true that assault weapons are used in a small percentage of crimes, although 1% is disputable in Miami for example 15 out of 79 homicides in 2006 involved assault weapons, [2] but the opposition ignore that large capacity magazines are used in a much higher percentage of crimes; between 14 and 26% before the 1994 ban. [3]  [1] Koper, Christopher S., et al., ‘An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994-2003’, Report to the National Institute of Justice, United States Department of Justice, June 2004, p.17   [2] Associated Press, ‘Assault-weapon attacks on rise in Miami area’, MSNBC, 14 September 2007,   [3] Koper, Christopher S., et al., ‘An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994-2003’, Report to the National Institute of Justice, United States Department of Justice, June 2004, p.18