There wasn't any blaming them (except their nationals are probably suppling the arms as usual).
Wait a second, I thought all the arms in Mexico were coming from gun shows in Texas? Was the President of Mexico lying??
I caught your earlier analogy ... I would use Animal Farm instead, excellent book, available in english, spanish, hebrew and arabic ... When the self-perceived downtrodden believe that they have a right to the same standard of living as the perceived overlords (whether they be they US or Israel or Dutch) there is the great left turn in logic. So they shoot the farmers, begin to starve since they can't run the farm themselves, and have to create a new oppressive society which makes the old society look downright utopian. I believe that this left turn of thinking has permeated central american culture through the teaching of liberation theology - they have a right to our wealth, and we are wrong for defending our borders.
The Mexican government evidently believes it as well; we're the big brother with a job, so we ought to take care of the familia they would say. So when an officer shoots a criminal while commiting a crime, it is the officer who is wrong because he represents The Man, and he is oppressing the downtrodden, and blocking access to wealth. And what is sick is that the same thinking has permeated American culture as well, but it comes out in different ways ... its the resentment of management, the wall street fat cats. We resent their wealth power and influence but instead of working hard, we wish to tear them down, hurt their profits, equalize the wealth without equalizing the risk or the labor. The constitution never protects equality of result, just opportunity.
I think Animal Farm is on most reading lists in the US, buts its used as a how-to book.