Updated at 2:13 p.m. Eastern.
Scotland freed the terminally ill Lockerbie bomber on compassionate grounds Thursday, letting the Libyan go home to die despite American pleas to show no mercy for the man responsible for the 1988 attack that killed 270 people.
The White House declared it the Scottish decision as Abdel Baset al-Megrahi left Greenock Prison and flew to Libya on an Airbus dispatched to Glasgow Airport, still insisting he was innocent.
Scotland's justice secretary said freeing the bomber was an expression of the Scottish people's humanity but U.S. family members of Lockerbie victims expressed outrage.
"I think it's appalling, disgusting and so sickening I can hardly find words to describe it," said Susan Cohen, of Cape May Court House, New Jersey, whose 20-year-old daughter, Theodora, died in the attack. "This isn't about compassionate release. This is part of give-Gadhafi-what-he-wants-so-we-can-have-the-oil."
Bert Ammerman, whose brother Tommy was killed in the bombing and who now is the president of the Victims of Pan Am 103, told CBS News that "today was the second worst day."
"The first was when Tommy died. But to see [al Megrahi] today, received like that," he said while shaking his head.
Some men outside the prison made obscene gestures as al-Megrahi's prison van drove by toward the airport.
Al-Megrahi, who had served only eight years of his life sentence, was recently given only months to live after being diagnosed with advanced prostate cancer.
Scottish Justice Secretary Kenny MacAskill said although al-Megrahi had not shown compassion to his victims - many of whom were American college students flying home to New York for Christmas - MacAskill was motivated by Scottish values to show mercy.
"Some hurts can never heal, some scars can never fade," MacAskill said. "Those who have been bereaved cannot be expected to forget, let alone forgive ... However, Mr. al-Megrahi now faces a sentence imposed by a higher power."
U.S. President Barack Obama said Thursday that his administration had made clear to Scottish authorities that Washington did not want the Libyan released and said it was "a mistake" to free him on grounds of compassion.
Mr. Obama said he hoped al-Megrahi would not be given a hero's welcome upon his return to Libya and instead be placed under house arrest.
According to a White House official, Secretary of State Hillary Rodham Clinton and Attorney General Eric Holder were among those to directly convey to the U.K. and to Scottish authorities the view al-Megrahi should serve out his term in Scotland, reports CBS News White House correspondent Peter Maer.
But, as CBS News legal analyst Andrew Cohen notes, al Megrahi "was in a Scottish prison subject to Scottish law and that means that Scotland gets to make the final call. Remember, many Europeans don't care for the way the U.S. dispenses justice, especially when it comes to capital cases. So this is a situation where the tables are turned."
Al-Megrahi, 57, was convicted in 2001 of taking part in the bombing of Pan Am Flight 103 on Dec. 21, 1988. He was sentenced to life in prison. The airliner exploded over Scotland and all 259 people aboard and 11 on the ground died when it crashed into the town of Lockerbie.
The former Libyan intelligence officer was sentenced to serve a minimum of 27 years in a Scottish prison for Britain's deadliest terrorist attack. But a 2007 review of his case found grounds for an appeal of his conviction, and many in Britain believe he is innocent.
In a statement following his release, al-Megrahi insisted he was wrongfully convicted. "I say in the clearest possible terms, which I hope every person in every land will hear - all of this I have had to endure for something that I did not do," he said.
White House spokesman Robert Gibbs said Thursday the United States disagreed with the decision to free al-Megrahi.
"We continue to believe that Megrahi should serve out his sentence in Scotland," Gibbs said. "On this day, we extend our deepest sympathies to the families who live every day with the loss of their loved ones."
"I don't understand how the Scots can show compassion. It's an utter insult and utterly disgusting," said Kara Weipz, of Mount Laurel, New Jersey, whose 20-year-old brother Richard Monetti was on board Pan Am Flight 103. "It's horrible. I don't show compassion for someone who showed no remorse."
In his statement, al-Megrahi said he believed the truth behind the Lockerbie bombing may now never be known.
"I had most to gain and nothing to lose about the whole truth coming out - until my diagnosis of cancer," he said, referring to an appeal against his conviction that he dropped in order to be freed. "To those victims' relatives who can bear to hear me say this, they continue to have my sincere sympathy for the unimaginable loss that they have suffered."
MacAskill said he stood by al-Megrahi's conviction and the sentence for "the worst terrorist atrocity ever committed on U.K. soil."
He said he ruled out sending the bomber back to Libya under a prisoner-transfer agreement, saying the U.S. victims had been given assurances that al-Megrahi would serve out his sentence in Scotland. But he said that as a prisoner given less than three months to live by doctors, al-Megrahi was eligible for compassionate release.
Compassionate release is an established feature of the Scottish judicial system when a prisoner is near death. According to officials, there have been 30 requests for release on compassionate grounds in Scotland over the last decade, 23 of which were approved. Scotland, which is part of Britain, has a separate legal system.
Al-Megrahi's return will be a landmark event in Libya and a cause for celebration. His countrymen see him as an innocent victim scapegoated by the West in a campaign to turn their country into an international pariah. Many will also view his release as a moral victory for their country.
Al-Megrahi will arrive Thursday night at Meetiga military airport on the outskirts of Tripoli, the Libyan capital. A few hundred Libyan youths prepared to greet him, while a military band warmed up. Some were dressed in T-shirts bearing al-Megrahi's picture and carried Libyan flags or placards with his image.
It was not immediately clear whether he would be taken to meet Libyan leader Moammar Gadhafi or go directly to a hospital for medical care.
A letter published Thursday showed that Libya had invoked human rights concerns in appealing to Scotland for al-Megrahi's release.
Abdulati Alobidi, Libya's Secretary of European Affairs, said under the International Covenant on Civil and Political Rights - a U.N. treaty - all those deprived of liberty must be "treated with humanity and respect for the inherent dignity of the human person."
Gadhafi engineered a rapprochement with his former critics following the Sept. 11, 2001, terrorist attacks. He renounced terrorism, dismantled Libya's secret nuclear program, accepted his government's responsibility for the Lockerbie bombing and paid compensation to the victims' families.
Western energy companies - including Britain's BP PLC - have moved into Libya in an effort to tap the country's vast oil and gas wealth.
Gadhafi lobbied hard for the return of al-Megrahi, an issue which took on an added sense of urgency when al-Megrahi was diagnosed with cancer last year.
Al-Megrahi was a well-known figure in the Scottish community near his prison, receiving regular treatment at the hospital and visited often by his wife and children, who lived in Scotland for several years.
Briton Jim Swire, whose daughter Flora died on Flight 103, welcomed the Libyan's release, saying many questions remained about what led to the bomb that exploded in the cargo hold.
"I think he should be able to go straight home to his family and spend his last days there," Swire told the BBC. "I don't believe for a moment this man was involved in the way he was found to be involved."
Among the Lockerbie victims was John Mulroy, the AP's director of international communication, who died along with five members of his family.
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