Well, there goes the “progressive” argument against banning them. From Engineering.com:

A new, high tech radar scanner could help make airports and secure facilities even safer with its ability to ferret out nearly undetectable 3D printed weapons.

Developed by Manchester Metropolitan University with funding from the UK’s Home Office and Metropolitan Police, the new device was built to scan people as they mill through crowded public spaces and sound the alarm if any threats are detected.

Using sophisticated signal processing the scanner sends a beam of radio waves into a crowd where they’re reflected back if a 3D printed weapon is detected. Once returning waves reach the origin device an onboard computer attempts to classify the signature of the signal using artificial intelligence algorithms. If a positive printed weapon match is made the device alerts a nearby operator who’ll be informed of the area in which a weapon was discovered.

More at the link. And, thanks to my Google search, I’ve discovered another interesting website that I’ve bookmarked and will be following.