PS - on the "fired casing" thing. If the cops find a fired casing at the scene, this database will allow them to narrow the search down to a specific maker and perhaps model (and caliber obviously). They still need to locate and obtain the exact firearm used and take that prefired casing, or fire a shot for comparision. Of course, if an abrasive object like a file were to accidentally rub against the firing pin at some point, the comparison will yield a negative result.
Just pointing out the weakness of that system, not advocating any shady actions.
