Criminology and Psychology

   Four of the corpses are sprawled over a shiny new Dodge Ram pickup truck that has been pierced so many times it resembles a cheese grater. The bodies are contorted in the unnatural poses of the dead - arms arched over spines, legs spread out sideways. The bloodied fifth man is lying three metres from the pickup. His eyes are wide open, his right hand stretched upward clasping a 9mm pistol - a death pose that could have been set up for a Hollywood film. It is a balmy evening in Culiacan, Sinaloa, near Mexico's Pacific Coast. The policemen had stopped at a red light when the gunmen attacked, shooting from the side and back, unleashing bullets in split seconds. A customized Kalashnikov can fire 100 rounds in 10 seconds. This is a lightning war. I arrive 10 minutes after the shooting and a crowd of onlookers is already thickening. "That one is a Kalashnikov bullet. That one is from an AR15," says a skinny boy in a baseball cap, pointing at a long silvery shell next to a ...