Having known many people from the interior states of Mexico I have long heard how, despite the prohibition, guns were usually commonplace with drug dealers and gang members in Mexico. Not to mention, this still does not make mention of the Mexican military weapons (and soldiers) found in the hands of drug cartel members.
http://www.nytimes.com/2009/02/26/us/26borders.html?_r=1&pagewanted=2
http://www.nytimes.com/2009/02/26/us/26borders.html?_r=1&pagewanted=2
