because they were also thought to be responsible for the massacre of up to 72 migrants from central and south america, and the reason foes migrants were slaughtered is because they would not work for the zeta cartel. until a few years ago the zeta cartel was nothing more than an assassin group, they were drug thugs. they broke off from the all important gulf cartel. they have become very powerful. they are responsible for much of the violence in mexico. they are thought to have killed two prominent politicians in recent weeks down there. 28,000 people, megyn, in the past four years killed in drug violence. it keeps inching closer to the u.s. border. felipe calderon the mexican president under severe criticism but with this shooting of 25zeta cartel members and with the arrest of edgar the barbie