This video is from 2010, but it’s still pretty cool. A beginner in aikido takes a gun from a thief. The technique he uses is kote gaeshi, translated as “wrist return.”
Use good sense: Do not attempt to take a weapon from someone unless you think you have to! If you can run away, then run away. This guy had good reason to think that if he didn’t take the gun, he was about to be shot.