They're called the Gringo Hunters. An elite division of the Mexican Police that tracks down Americans who crossed the border to elude law enforcement. We embed with the unit as they track down two Americans suspected of crimes abroad.

Just before his highly anticipated Super Bowl halftime show, R&B superstar Usher opens up. It's going down in Sin City, where his residency has dominated the strip. And we revisit his career - from baby-faced church choirboy to the reigning king of R&B.