The deeper I dug, the more complicated Lockerbie became and there have been times that I don't know what to believe.

In December 1988, Pan Am flight 103 exploded over the Scottish town of Lockerbie, killing all 259 people on board as well as 11 on the ground. I was a teenager by the time Libyan intelligence officer Abdelbaset al-Megrahi was convicted of the bombing in 2001 and, when he later died, I thought that was largely the end of the story. The case still rumbles on and, later this year, a man suspected of making the bomb which blew up the plane, Abu Agila Masud, goes on trial in Washington DC. As part of a Radio 4 Intrigue podcast series, I had an opportunity to delve into this complex case with fresh eyes. The deeper I dug, the more complicated Lockerbie became and there have been times that I don't know what to believe. Jim Swire, on the other hand, is sure what he believes - and it is not the official story. His daughter Flora died in the bombing, but he is convinced that whoever killed her got away with mass murder. Swire believes Megrahi is innocent, even befriending the convicted bomber up until his death in 2012.