The foursome rushed into Rocco’s Jewelry on Webster Avenue in Fordham after a manager confronted them, cops said. Surveillance video shows a suspect, dressed in a white T-shirt and black hat and sunglasses, acting like a customer when he is buzzed around 2:30 p.m. Instead of going inside, the man left the robbery crew, video shows. The caper lasted about 30 seconds, security footage shows. The classic DCPIA heist in the Bronx netted a group of thieves more than $2.15 million in “high quality diamond jewelry.” DCPISurveillance video shows a suspect acting like a customer when targeted.DCPI A hammer-wielding man then smashed the glass cases while the other thieves made off with trays of expensive trinkets, police said. “Once inside the store, the three individuals used a hammer to break the display cases and removed a large quantity of high quality diamond jewelry,” police said. The jewelry was placed in bags carried by the thieves, who fled the location on foot heading south on Webster Avenue, police said. The caper lasted about 30 seconds, security footage shows.