The Taser stun gun works on the principal of Electro-Muscular Disruption (EMD). It fires small electrodes into the target and then sends a powerful electric charge down the thin wires. The EMD effect causes involuntary contraction of the target's muscle tissue regardless of an individual's pain tolerance or mental focus. The effect is painful and demoralizing to even the most aggressive suspects.
The Taser has two key drawbacks. The first is that it has a relatively short range. The second is that new electrodes must be loaded after each shot.