[The following are excerpts from an article in today's edition of The Wall Street Journal.]
Mr MacAskill, in granting compassionate release to Mr Megrahi, relied on a report from the head administrator for Scotland's prison health service saying that it was reasonable to estimate that Mr. Megrahi would die from prostate cancer within three months—though the report didn't present medical evidence directly supporting that prognosis.
At the time, Scotland's legal system was weeks away from facing a potentially embarrassing appeal over Mr Megrahi's still hotly-debated conviction for the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, that killed 270 people. Mr Megrahi dropped his appeal two days before Mr MacAskill's decision to release him.
The evidence that led to Mr Megrahi's conviction has long been questioned by some legal experts.
"On absolutely crucial factual points, without which they could not have convicted [Mr Megrahi], their decision was simply contrary to the evidence," said Robert Black, a senior lawyer and former professor of Scots law at the University of Edinburgh. Mr Black helped design the special trial for Mr Megrahi held in the Netherlands under Scottish law. (...)
Scotland first fended off a legal appeal by Mr Megrahi in 2002. But in 2007, a review by the Scottish Criminal Cases Review Commission identified six grounds on which it concluded that there "may have been a miscarriage of justice" in the case. That triggered a second appeal for Mr Megrahi, which was due to be heard in the fall of 2009.
The appeal was set to focus on issues that had been challenged, such as the validity of statements by a key witness.
With his compassionate-release application hanging in the balance, Mr Megrahi met on Aug 6, 2009, with Mr MacAskill.
On Aug 18, Mr Megrahi dropped his appeal. Two days after that, Mr MacAskill agreed to release Mr Megrahi on compassionate grounds.
Some politicians and critics have said Mr MacAskill was influenced by the pending appeal.
"Kenny would want to do what he would genuinely think is the right thing, and would try and protect the Scottish justice system," said Margo MacDonald, an independent member of the Scottish Parliament. Scotland defends the conviction, and denies Mr MacAskill traded Mr Megrahi his freedom in exchange for the dropped appeal.
"Megrahi was convicted by a Scottish Court, and Scottish Ministers do not doubt the safety of the conviction," said a spokesman for Mr MacAskill.
A spokeswoman for the Scottish prosecution service said the service "has supported the conviction vigorously and stood ready, willing and able to do so throughout the appeal process which Mr Megrahi abandoned."
Mr Megrahi wasn't legally required to drop his appeal to win compassionate release. He would have been obligated to do so under a separate petition he had filed to be returned to Libya under a prisoner-transfer agreement, but Scotland rejected that in favor of compassionate release.
Mr Megrahi was convicted based on a mix of physical and circumstantial evidence. Police traced fragments of clothes from the suitcase in which the bomb was detonated to a shop in Malta, whose owner, Antony Gauci, identified Mr Megrahi as looking "a lot" like the purchaser. Based on the evidence, the court concluded that the clothes were bought on Dec 7, 1988, a date when Mr Megrahi was staying in a nearby hotel.
The court also heard evidence that Mr Megrahi was at a Malta airport at a time when baggage was loaded onto a flight to Frankfurt, where it would be transferred to a flight to London and onto Pan Am Flight 103.
Other key parts of the prosecutor's case involved fragments of the bomb's timer, traced to a Swiss firm that admitted to dealings with Mr Megrahi and the Libyan military.
But when the Scottish commission reviewed the conviction, it said there was new evidence that raised questions about the identification by Mr Gauci. Though the commission declined to disclose this material, Mr Megrahi has since released documents claiming fresh evidence, including inconsistencies in what Mr Gauci had told prosecutors.
Mr Gauci's testimony about the date varied, according to these documents, and at one point he said the clothes were bought on Nov 29, 1988 — not Dec 7. The shopkeeper had also said Mr Megrahi bought the clothes before the switching on of local Christmas lights, while evidence submitted by Mr Megrahi's defense claims to show the lights were turned on earlier.
There also was previously undisclosed evidence that suggested that Mr Gauci had expressed interest in a financial reward prior to testifying, which Mr Megrahi's lawyers said raises questions about the reliability of the witness.
The documents quote extracts from a British police officer's diary that said the Department of Justice offered Mr Gauci $2 million if he gave evidence. The Department of Justice denies the offering such a payment. Mr Gauci couldn't be reached for comment.