Their crimes resemble high-octane Hollywood action movies: a sports car speeds through a Dubai shopping mall, crashing into the windows of a Graff jewelry store. Masked, gun-wielding men jump out of the car, and stuff fistfuls of diamonds into their satchels before screeching off. In London, they took all of three minutes to make off with {dollar}30 million in diamonds. They are captured – not in person, but on surveillance tapes that record their...