Yes, even modern technology has uses. We can use a 3D printer to print fingerprints, copy keys, and make disposable guns.
A gun SHOULD be disposeable. Because for those who act without state permission, it is evidence that can be used against you. A good 3D gun could be used, then thrown in the fire to be melted.
One can use smartphones and 3D printers to copy fingerprints now. One can even take a picture from up to 200 feet away and get the prints.
You can now copy keys, even the Do NOt Duplicate ones, with 3D printers.
It is also possible to print up the DNA of a person if you have a sample. A hair, sweat, buccal swab or used water bottle will work.