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.
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Convicted Lockerbie Abdelbeset Ali Mohmed al Megrahi dies after cancer battle
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Some of the victims' families believe the Libyan was not responsible for the bombing
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He was freed from prison in Scotland in August, 2009 on compassionate grounds
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British PM David Cameron says al Megrahi should never have been released
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Despite being given just a few months to live, he survived for more than two years, sparking anger against the @placeholder authorities and accusations in the British press that a deal had been struck with Libya.
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He believes al Megrahi was innocent and presents his reasons in his book "Megrahi: You are my jury - the @placeholder evidence.'"
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On Monday, Scotland's First Minister told British media that the @placeholder case was still a live investigation.