3D Printed Gun
Today, there is more access to 3D printers in the mainstream market. Finding these items might be tricky as they cannot be detected by x-rays and metal detectors, yet they can successfully fire off several shots.
The TSA confiscated a gun created from a 3D printer loaded with live ammunition from a traveler who decided to leave the revolver behind and boarded his flight.
Luckily there were no impacts to the airport operations.