London (CNN) -- Abdelbeset Ali Mohmed al Megrahi, the only person convicted in connection with the Lockerbie airline bombing that killed 259 people on board Pan Am Flight 103 and 11 on the ground, went to his grave protesting his innocence.
And there are others who believe that Megrahi, who died on Sunday from cancer, was not responsible for bringing down the jet over Scotland in 1988, including some of the victims' families.
Why does the tragedy continue to raise questions? CNN examines the issues.
Why was al Megrahi convicted?
After a nine-month trial that concluded in January 2001, a Scottish court based in a former U.S. base at Camp Zeist in the Netherlands, convicted al Megrahi of the murders and he was sentenced to life in prison with the condition that he serve at least 27 years before being eligible for parole. Scotland does not have the death penalty.
The trial followed years of negotiation with Libya, after British and American investigators indicted two men for the crime in 1991. Read More