LET’S assume for the sake of argument that Abdelbaset al-Megrahi, the only man to have been convicted of the obliteration of Pan Am Flight 103, was guilty as charged. In total, on 21 December, 1988, he murdered 270 people, 259 of whom were on board the ill-fated plane and 11 residents of the Dumfriesshire town of Lockerbie. By some distance that would qualify the Libyan as the biggest killer in this country’s history. Subsequently, in 2001, three Scottish judges, sitting in a special court in the Netherlands, sentenced him to life imprisonment, with a recommendation that he should not be considered for parole until he had served at least 20 years.

In the event, Megrahi served little more than eight years before he was sent back to Libya diagnosed with terminal cancer. The person solely responsible for a decision that angered and bemused many people – not least the majority of the victims’ families – was Kenny MacAskill, Scotland’s then Justice Secretary. This book is his attempt to explain how he came to that decision, and to justify it. It makes for painful, disturbing and difficult reading. For if, as MacAskill still appears to believe is the case, Megrahi was instrumental in the Lockerbie bombing, and the verdict was safe, then the rationale for treating him with a compassion alien to his actions is hard to swallow.

That he was dying is beyond doubt. But that does not mean he deserved to be allowed to spend his last months at home in the bosom of his family? Prisoners who have committed far less heinous crimes than Megrahi die regularly in Scottish jails. They are not given special dispensation. Indeed, as MacAskill acknowledges, Megrahi’s family were able, if they so chose, to live in a house in Newton Mearns, near both prisons in which he was held and to visit him regularly.

In one of the more farcical passages in his book, the author notes that one of the problems concerning the use of this house as a possible place where Megrahi could stay on his release was that one of the neighbours was “a major sports commentator for Sky Sports TV” who might allow his garden to be used for “minute-by-minute coverage”. Nevertheless, maintains MacAskill, Megrahi was released “following the laws adhering to the values I believe we hold in Scotland”.

But what appears to have been instrumental was an agreement reached between the Libyan dictatorship of Colonel Gaddafi and the Labour government of Gordon Brown who imposed a Prisoner Transfer Agreement on Scotland. In effect, this paved the way for Libya to request the return of Megrahi. As MacAskill relates, the Scottish Government was adroitly outmanoeuvred and reduced to negotiating concessions from Jack Straw, the Home Secretary, including the devolving to Holyrood of the use of air guns which was “blighting communities across the land”. Nothing, however, came of this and the PTA was signed in April, 2009. “The rights of the Scottish Government,” writes MacAskill, “never mind the interests of the victims, were ignored. They [Brown, Straw and co] delivered what the Libyans requested and were going to leave it to the Scottish Government to face the issue of accepting or rejecting a future application for prisoner transfer for Megrahi that would no doubt come in.”

ALL of which, of course, presumes that Megrahi was culpable. Much of the first half of MacAskill’s book is devoted to a reprise of events that will yield little new to those familiar with the Lockerbie saga. Drawing on a limited number of sources, mainly the Scottish Government’s in-house website, and airily dismissing the work of authors such as John Ashton, who was a member of the legal team representing Megrahi, the former Justice Secretary would have us believe that his faith in the Scottish judiciary is unshaken. “I accept the conviction and sentence imposed,” he said in the course of announcing his decision to release Megrahi.

Elsewhere, however, he acknowledges that had the crucial evidence of Tony Gauci –the Maltese shopkeeper who said he sold Megrahi the clothes that were found among the debris from the Pan Am plane – been dismissed from the prosecution case it “would have resulted in an acquittal”.

This, then, is where one finds MacAskill’s argument unpersuasive. There is no doubt that Gauci – described by Lord Fraser of Carmyllie, a former Lord Advocate, as “not quite the full shilling” and “an apple short of a picnic” – was a poor and unreliable witness. For instance, when first asked to detail what Megrahi looked like he described someone who was quite different from the police’s chief suspect. He also had trouble fixing on a date on which Megrahi had visited his shop. Apparently, Megrahi paid for his purchases in cash which Gauci said cost £76.50 which, had there been a receipt, would have saved a lot of head-scratching. Ultimately, he identified Megrahi after he was shown photographs of him by the police. Was he influenced by the fact that he’d previously seen pictures of him in a magazine? Or did the promise of a $2m reward help jog his memory? The depressing fact is that after 28 years, the true story of Lockerbie remains untold.