[AuntB]

“Mexican people take the guns into Mexico, or Mexican military people SELL these guns to narcos.”

Exactly, and most of those ‘mexican people’ are illegal aliens.

02/18/11 | AP via FOX
PHOENIX – Federal prosecutors in Arizona say two illegal immigrants from Mexico have been indicted after they were found to possess a combined 222 assault rifles and five pistols that authorities say were headed to Mexico. Prosecutors said Thursday the two immigrants possessed the weapons in May and August, and that the guns were later seized in the border city of Laredo, Texas.
http://www.freerepublic.com/focus/f-news/2675837/posts

[MasterGunner01]

Between 2003 to 2009, the Mexican Army had 150,000 desertions. Guess who took their Mexican-government supplied arms with them? Can you say “Mexican Army deserters”? We knew you could — except for the U.S. and Mexican governments.

This piece from Wikipedia pretty well summarizes what comes from where: http://en.wikipedia.org/wiki/Mexican_drug_cartel

Of course, let's not forget the ATF involvement in actual trafficking of guns between the U.S. and Mexico: http://www.examiner.com/gun-rights-in-national/a-journalist-s-guide-to-project-gunwalker