nk497 writes "Police in Manchester have arrested a man and seized what they claim are 3D printed components to a gun. They made the arrest after a 'significant' discovery of a 3D printed 'trigger' and 'magazine,' saying they were now testing the parts to see if they were viable. 3D printing experts, however, said the objects were actually spare parts for the printer. 'As soon as I saw the picture... I instantly thought, "I know that part,"' said Scott Crawford, head of 3D printing firm Revolv3D. 'They designed an upgrade for the printer soon after it was launched, and most people will have downloaded and upgraded this part within their printer. It basically pulls the plastic filament, and it used to jam an awful lot. The new system that they've put out, which includes that little lever that they're claiming is the trigger, is most definitely the same part.'"