{video} Dramatic new video of the brazen midday holdup of a jewelry store in Midtown’s Diamond District reveals the moment an armed trio takes workers hostage. The nearly half-minute of additional surveillance footage of the heist — released by cops Monday morning — shows one of the hat-wearing bandits in a back room at Avianne & Co. coolly posing as a customer before reaching under the table and whipping out a silver handgun on three employees. Meanwhile, in the front of the store, the other two crooks point their handguns at a single store employee, who raises his hands, the video shows. The crooks tied up the four ... (full story)