Commissioner said Liberator pistol suffered "catastrophic misfire" during testing.

techworld.com

The police used the Liberator pistol blueprints produced by US-firm Defense Distributed. The original plans for the gun were downloaded more than 100,000 times before the company pulled them from its site under pressure from the US State Department.

Police believe that despite this, the files are still circulating.

The commissioner said that a Liberator pistol had experienced a catastrophic misfire during testing. The failure would have been capable of seriously injuring the person using the firearm, the police chief said.

The police spent $35 on materials to create a Liberator and used a $1700 desktop 3D printer. The only metal parts used in the pistol's construction where the firing pin, created with a nail, and a .380 ACP calibre pistol cartridge. The all-plastic body means that the pistol is hard for security forces to detect.

Inspector Wayne Hoffman said the creation of a pistol took the police around 27 hours. Assembling the pistol's 17 parts took around a minute. Hoffman said that the police had exactly followed the original instructions for creating the Liberator, with a number of modified versions of the file currently in circulation.