With increasing gun crime Britain's police forces often have to match fire with fire. But terrible accidents happen.

Earlier this month a man was shot dead by police after brandishing an unloaded home-made shotgun. Panorama investigates two other recent controversial episodes where police mistakenly shot innocent men.

Tom Mangold asks why so many guns are out, why the policy of shoot to stop frequently means shoot to kill, and why Britain lags behind in the use of non lethal force.

Production Team:
Reporter Tom Mangold
Producer Jonathan Jones
Assistant Producers Tamsen Courtenay & Phillip Wearne