hernandez. investigators say he was with the center of the lelaborate straw purchasing scheme. >> doesn't stand out in a crowd. >> reporter: according to atf investigators, hernandez recruited a crew to purchase guns across houston. he bought six weapons and ammunition at this gun shop, one weapon later connected to the kidnapping and murder of a mexican businessman. hernandez also admitted to buying weapons in the infamous 2007 alcapulco massacre where seven people, including four police officers, were slaughtered by a dozen armed drug traffickers. atf special agent in charge, dewey webb showed us some of the group's favorite hardware. >> dozen different versions of these on the market today. >> reporter: hernandez purchased four weapons here at this shop. we spoke with the owner. he didn't want to go on camera. he told us a few weeks after that, hernandez returned