Lockerbie Trial: The Background - A long and painful road to justice

NOW COMES the hard bit. The United Nations might have taken more than seven years to persuade the Libyan leader, Colonel Muammar Gaddafi, to hand over the two men accused of the Lockerbie bombing but convictions are still a long way off.

The spotlight will now turn on Britain and the United States to see whether their evidence against the two men will come up to scratch. Some observers think it will not.

There could be nothing more inglorious and embarrassing for the two governments than the presiding judges throwing the case out of court. This is unlikely but not impossible, because the evidence so far presented by the authorities is by no means compelling and Scottish law is particular.

But the trial may not beginfor some time. The two Libyans, Abdel Basset Ali al-Megrahi, 47, and al-Amin Khalifa Fhimah, 43, will be held in custody in the former US Air Force base at Camp Zeist in the Netherlands.

By the terms of the unprecedented Anglo-Dutch agreement, until the end of the trial the base has been designated Scottish territory so that Scottish law can prevail.

The three Scottish judges who will hear the case without a jury have not been appointed. The prosecution will be led by the Scottish Lord Advocate, Lord Hardie.

The case centres on events of more than a decade ago. At 1902 hours on 21 December 1988, a New York-bound Boeing 747 designated Pan Am 103 exploded at 31,000ft and crashed on the town of Lockerbie in the Scottish borders, killing 270 people on board and on the ground.

The passengers were mainly American and British. Many were students returning home for Christmas.

Within days, forensic scientists said a bomb had caused the disaster, described as "the most appalling crime since the Second World War".

Who put the bomb there? No one claimed responsibility. A variety of theories quickly emerged: the Iranians did it as revenge for the accidental shooting down of one of their airliners by the USS Vincennes in July 1988; Palestinian terrorists did it to eliminate a CIA team that had been preparing to rescue Western hostages in Beirut; the Libyans did it as revenge for President Ronald Reagan's bomb attack on Tripoli in 1986.

After a three-year investigation headed by Chief Inspector Watson McAteer from the Dumfries and Galloway police, helped by an FBI team, the finger pointed towards Tripoli. Ch Insp McAteer's detectives had visited 23 countries, collected more than 3,500 photographs and taken more than 15,000 statements.

Forensic scientists believed the bomb was made of 10 to 14 ounces of Semtex explosive hidden in a Toshiba cassette recorder inside a brown Samsonite suitcase.

In November 1991 formal charges were laid. Although Colonel Gaddafi is said to be the eminence grise behind the bombing he has not been charged. The charges are against two "small fry" Libyans who, unfortunately, look as though they could have born to grace an Interpol wanted poster. They are accused of being the agents who planted the bombs on behalf of Libyan intelligence services.

Both had been working as airline officials for Libyan Arab Airlines in Malta.

The prosecution will claim they smuggled a bomb in an unaccompanied suitcase into the international airport's luggage transfer system and they used baggage transfer tags on the suitcase to make sure it was transferred on to Pan Am 103 at Heathrow.

Key evidence against the two men centres on a small fragment of electronic circuit board found in the scattered baggage of the wreckage. It is said to be part of a timing device sold by a Swiss company, MEBO, to Libya in 1985.

Tags on the clothes within the bomb suitcase show they were of Maltese origin and sold in only one shop in Malta. The shop owner was shown a series of photographs of Arab men and is said to have picked out al-Megrahi as the purchaser of the clothes. But in the intervening seven years doubt has fallen on key elements of the prosecution case. The Maltese authorities and airline do not accept that unidentified luggage left Malta. The circuit boards were also sold elsewhere, including to the terrorist-supporting Stasi, the malevolent intelligence agency of the former East Germany. The Maltese shopowner's statements show he consistently said the man was older and taller than al-Megrahi.

But in the prosecution's favour, more recent evidence, from a mysterious Libyan defector, seems to confirm Colonel Gaddafi's involvement.

The families of the British victims are well aware of the frailty of the prosecution case.

The Reverend John Mosey, who lost his 19-year-old daughter, Helga, said: "Whether the judge throws it out of court at the beginning for there not being enough evidence for a bona fide case or whether they are found guilty, we will have the evidence examined in a court of law and found out who knew what and why this very preventable disaster was allowed to happen."

Although the families welcome the trial this is not the end of the line for them. The Rev Mosey said the main aim - to hold an independent inquiry - has been blocked by the possibility of criminal trial.