Being killed by your own firearm is not the way any of us wants to go. Unfortunately, many law enforcement officers have been disarmed and subsequently killed with their own gun. Some citizens have also met this unfortunate end. There are three things that can help prevent being disarmed by an assailant: awareness, retention holsters and weapon retention training. Cover vs Concealment : Cover, Most things we think might stop bullets wont. The best cover in the world is a wall of reinforced concrete with a triple layer of sandbags behind it, but we don’t see that very often. What will stop a bullet? Piles of dirt are the best, and a firing position in a ditch, depression or behind a hill is great. Next to that, concrete or brick walls are good, as are the engine compartments of vehicles (especially large trucks.) In a real shootout properly using cover is very important. Of the things you control it is what has the best chance of keeping you alive. Concealment, is something that prevents an enemy from seeing you, or at least from seeing you completely. It is not as good as cover, but in keeping an enemy from having a complete sight picture it is far better than standing in the open. Things that could commonly be used as cover include the walls of normal wood frame houses, small trees and foliage or car bodies.
Edged weapon defense: a concept called the 21-Foot Rule has been a core component in training officers to defend themselves against edged weapons.