Britain’s biggest mass murder

On 21 December 1988 Pan Am flight 103 left Heathrow Airport bound for New York. When the Boeing 747 was 31 000 feet over Lockerbie in Scotland it dropped from the sky, killing all 259 passengers, the crew and 11 people on the ground. The devastation was made worse by 91 tonnes of fuel exploding when one of the fuel tanks hit the ground. But what was originally thought to be a tragic air accident turned out to be Britain’s biggest mass murder. How was this conclusion reached?