Tony Long is Britain's most prolific police marksman. Deployed on hundreds of dangerous operations to bring down terrorists, killers and hostage takers, he has been behind some of the UK's most controversial police shootings. But it was the death of Londoner Azelle Rodney in 2005 that landed him in court for murder and brought his career to an end. Long reveals what it is like to shoot and kill people in the line of duty, and how his life crumbled during the Rodney case