To kill with one shot needs a specialist. In war, choosing a perfect concealed position and knowing exactly when to pull the trigger takes a special talent. But some such as John Wilkes Booth, murderer of president Abraham Lincoln, prove that any madman with a gun can make history in a random moment.

In 1963 President John F. Kennedy was killed by shots to his back and head. Despite being surrounded by security and in a public place, his killer knew where to hide and when to shoot. For three weeks in October 2002, a sniper in a Chevrolet Caprice terrorised Washington DC, Maryland and Virginia. In these three weeks, and at various times and locations, ten people were shot dead and three were critically injured after being struck by the mysterious marksman. Two days after the last murder police identified the sniper and his accomplice - their murderous road trip was over.