Here is a demonstration.
A car thief holds you up.

Our patented arm retracts to assault the thief in the private area.

Force is applied to neutralize the threat. As you see, the thief has dropped his weapon.

The hand of the arm is detached to ensure no counter attacks.

Then, you can safely drive away and report the event. Only police stations has the special key to remove the device, forcing the thief to turn himself in.

Crime does not pay!