roxie williams, however, wasn't crazy.acting on an insider's tip, the sheriff's department discovered workers at burr oak had been removing headstones, digging up coffins and dumping remains in mass graves so they could resell the plots. it soon became apparent an entire community had been deceived. hundreds of bodies were thrown out over a period of many years without anybody figuring out what was going on. >> tom dart: we first came out here, we found femurs, skulls, parts of jaws just laying out in the open. >> cooper: laying out on the ground? >> dart: oh, yeah. i mean, we found one right over here. >> cooper: cook county sheriff tom dart led the investigation at burr oak. and this was all about greed? >> dart: oh, absolutely. this was all about greed, and overarching that is the fact that these areas are so horribly unregulated, it allows for that to happen. >> cooper: when you say it's unregulated, what do you mean? >> dart: there was no records of anything. there was no records of how many people are supposed to be