Here is a great 2 minute video ("Rival gunmen clash in Nayarit: 28 deaths reported") from a Mexican news station posted on YouTube via Borderland Beat. The video displays an engagement aftermath - that would be dead cartel foot soldiers in body armor/tactical gear.
We don't usually see many such body armor images. Since we are getting armored cars showing up more and more in Northern Mexico along with all the military infantry weapons (frag grenades et al) the need for body armor should come as no surprise.
Also -- apparently a Mexican Federal Police helicopter was engaged by Knight's Templar small arms fire and forced to land yesterday. See "Knights Templar attack Federal Police helicopter in Michoacan".
Dr. Robert J. Bunker