But CBS News Reporter Pamela McCall reports British families of those killed in the 1988 Lockerbie bombing want the trial widened to include allegations contained in a CBS 60 Minutes report that Iran was behind the bombing.
Speaking from the trial underway in the Netherlands, a spokesman for the families, Jim Swire, said the evidence should add to the trial - not undermine it.
"Really, the underlying situation is that these allegations should be incorporated in the evidence heard in court," Swire told CBS News.
"I'm very grateful that this information has come out at this time," Victoria Cummock, whose husband was one of 270 people killed in the bombing, said Monday on CBS News' The Early Show. "Many of the families for years have believed it was a conspiracy among countries between Iran, the Syrians, the Palestinians and this group, and that the Libyans were just the bagmen - the men that got the bob in a bag and on the plane."
Court officials at the trial refused to comment on the report, or whether the defector might be called as a witness. Legal experts say allegations of Iranian involvement in the bombing would not necessarily bear on the guilt or innocence of the Libyan defendants.
Meanwhile, defense lawyers attacked prosecution forensic witnesses on Monday, trying to sow doubt over exactly how the jumbo jet was blasted out of the air.
Iran was initially blamed for the attack, which killed all 259 people on board and 11 residents of the Scottish town of Lockerbie. It had vowed the skies would "rain blood" after a U.S. warship shot down an Iranian passenger plane six months earlier.
Attorneys wrangled Monday over highly technical jargon concerning explosives, baggage containers, suitcases and scraps of clothes that fell out of the sky amid thousands of pieces of flaming debris.
The defense need only create "reasonable doubt" in the minds of the panel of three judges hearing the case to win an acquittal.
It suggested Monday that two key fragments of wreckage had been contaminated with several kinds of explosive residue during British laboratory tests and not just by one kind from a bomb in the plane's hold.
Defense lawyer Richard Keen questioned former Defense Evaluation and Research Agency (DERA) forensic scientist John Douse on possible sources of contamination, including storage procedures and equipment used to prepare samples.
Douse dismissed Keen's arguments.
"That is unscientific. ... I have conclusive proof which I believe can refute this," he said from beside the reconstructed remains of the shattered aircraft luggage container said to have been torn apart by the bomb.
But Douse confirmed that his agency had not been able to test fragments of an electronic timer and the tape recorder thought to have hidden the bomb, citing cost savings at the laboratory.
"I would have given my right arm to examine them all," he said.
Former DERA forensic explosives director Thomas Hayes, testifying Monday after Douse, told the court he was certain a bomb in a brown Samsonite case had destroyed the jet.
"It was established without any doubt that this item had been subjected to a large internal explosion and therefore had originally contained an explosive device," he said.
Hayes said the nature of the damage indicated the suitcase had been either on the floor of the baggage container or on top of another case, corroborating blast pattern evidence from previous witnesses.
His testimony could hamper defense hopes to show that the bomb exploded outside the container and therefore could not have been planted in a suitcase by the accused.
The prosecution says the defendants were Libyan intelligence agents who used cover as employees of Libyan Arab Airlines to put a bomb in an unaccompanied suitase in Malta, which was eventually loaded onto the doomed flight in London.
The defense is expected to blame Palestinian extremists operating in Frankfurt.
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