A look at the history of the gruesomely violent struggle between the Sinaloan and Zeta cartels for money, land and political power by any means necessary.

By Tracy Wilkinson
Los Angeles Times
May 27, 2012, 8:00 p.m.

CULIACAN, Mexico — The cartel henchman
nicknamed "El Loco" was reported behind the latest atrocity in Mexico's
ever-more-depraved drug war: mutilating 49 people and piling their bodies —
heads, hands and feet missing — by the side of a road leading to the U.S.
border.

Authorities say he acted this month on orders from the top
commanders of the brutal Zeta paramilitary force, who wanted to send a message
to the long-dominant Sinaloa cartel and its allies, in a new phase of a conflict
that has claimed more than 50,000 lives in less than six years.