The release of Abdelbaset Ali al-Megrahi, the man who was convicted of blowing up a Pan Am plane over Lockerbie, Scotland in 1988, has prompted outrage and condemnation from U.S. and British officials, even as doubts linger about the legitimacy of the conviction.

Scottish Justice Minister Kenny MacAskill released Megrahi on compassionate grounds Thursday and allowed him to fly back home to Libya.

Megrahi, 57, is suffering from end-stage prostate cancer and is said to only have three months to live.

The Libyan national has been imprisoned in Scotland since 2001, and lost his last appeal in the case in 2002. He was sentenced to a minimum of 27 years in prison but only served eight years before being released today.

MacAskill wrote in his decision that “our justice system demands that judgment be imposed but compassion be available.”

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The American reaction to MacAskill’s decision which was swift and strong, mentioned justice, but not compassion.

“The interests of justice have not been served by this decision,” said U.S. Attorney General Eric Holder in a statement. Secretary of State Hillary Clinton also disagreed with the decision, saying that the bombing was a “heinous crime” and that Megrahi should serve out the entirety of his sentence in Scotland.

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Even some British officials are at odds with Scottish authorities over the decision. Conservative party leader David Cameron called MacAskill’s decision “nonsensical.”

However, Labour Chancellor Alistair Darling noted that his government did not have any say in the matter because under the devolved system of UK governance, Scottish authorities are the only ones with jurisdiction over judicial decisions in Scotland.

On December 21, 1988 Pan Am Flight 103 was en route from London to New York when it exploded in mid-air and crashed into the town of Lockerbie. The death toll was 270, including 189 Americans. Many of those who died were Syracuse University students returning from a semester abroad.

Megrahi was the only man ever convicted for the crime, even though he had an alleged co-conspirator. The case was largely circumstantial and hung on shreds of evidence such as a fragment of circuit board, Megrahi’s movements in the day before the bombing, and a false passport.

Many in Scotland and the U.S. are convinced of Megrahi’s guilt, but others, including some relatives of the victims, are not convinced due to the many unanswered questions and inconsistencies in the case.

In fact a 2007 review of his case found grounds for his conviction to be appealed, which Megrahi initially pursued. However, just a few days before being released he dropped the appeal, which means that additional evidence was not heard. It is still possible that an independent inquiry may be launched to examine some of the issues and questions that still surround the case.

Some foreign policy experts even suspect Iran may have been involved but believe that the U.S. never pursued that angle in order to not to upset fragile relations with the country. Libya, on the other hand, was a pariah nation with an unstable leader who may have been seen as a convenient scapegoat.

Megrahi, a former Libyan intelligence agent, expressed his profound sorrow for the loss of life in the tragedy, but continues to proclaim his innocence.

By Karen Elowitt for PeterGreenberg.com.

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