The Firearm Blog has done some extensive research and thoroughly debunked the widespread claim that American "assault rifles" are causing violence in Mexico.
For the past few months the media has been awash with articles discussing a new disease spreading across the USA-Mexican border, destroying lives and fueling the drug trade. The pathogen is the infamous “assault rifle” and the reason for the spread of arms is lax American gun laws, or so the American public is being told again and again.
Finally two reporters from Fox News, William La Jeunesse and Maxim Lott, took the time to look into the figures behind recent politicians’ speeches and discovered that only 13% of firearms confiscated in Mexico were of US origin. While it was a breath of fresh air to read an honest piece of journalism, I was still not satisfied with the number. It seemed incredible that an organization that is able to smuggle up to $48.4 billion [PDF link] worth of drugs into Mexico and from there export them to the US with apparent impunity are forced to purchase 13% of their arms from US gun stores selling civilian legal semi-automatic firearms, rather than the global arms black-market where just about anything can be purchased if you have the money.
There's more going on than meets the eye.
Firstly, the Mexican police seem to have either little understanding of the firearms they are confiscating, or little command of the english language to interpret what they have captured. For example, in this press release from last year, they list this rifle “Un rifle marca Nickel Steel Barrel, matrícula 440236, calibre 30mm” (English: “A rifle brand Nickel Steel Barrel, number 440236, size 30mm”, emphasis mine). The “brand” was obviously read off the barrel. They also regularly name the same type of firearm under varying names. For example MAK-90 Norinco semi-automatic AK-47 clones are sometimes called MAK-90, Mark-90 or MK-90 or just “Norinco”. They do not appear to be able to keep consistent records. The police regularly make many other sloppy errors but I will not list them all.
Secondly, despite the significant desertion of Mexican soldiers who likely took thier M16 rifles with them (150,000 soldiers deserted in the past 6 years out of a force of 183,700 active personal) the Mexicans have kept very quite about M16 rifles being confiscated. I only managed to find evidence of three M16 rifles captured in the past 12 months. This does not make sense considering the vast quantity of these arms almost certainty exist in the hands of Mexican criminals.