US inventor demonstrates armoured backpack shield
Recent mass killings in the US have prompted one parent and inventor to devise an armoured shield that could fit in a student's backpack.
Kerry Clark, who came up with the idea after the Virginia Tech shooting in 2007, claims that his invention can stop a bullet from 16 feet away.
The panel is designed to stop rounds fired by handguns, but not by rifles.
However, there are doubts about the effectiveness of his backpack shield and some sceptics argue that it is more likely to cause anxiety than offer comfort.