Drug war in mexico is escalating. who are the killers behind these cartels? jennifer griffin is bringing you the inside story. >> reporter: their tactics rifle that of al-qaeda, executions, torture, beheading, mexican core tells have skied more than 10,000 people since january, five times -- five times the number killed three years ago before president calderon deployed his military. >> the cartels don't have to work like colombia did for a middleman in florida, or texas or anywhere. they have people they know >> reporter: family and friends who move with ease across a porous border. a 40 bill...