NEW YORK (AP) -- A jury's conviction of the al-Qaida spokesman who warned Americans that the "storm of airplanes" would not stop after the Sept. 11 attacks prompted Attorney General Eric Holder to claim victory for the civil court system, signaling terror suspects arrested in the future in the U.S. or abroad will routinely face justice in civil courts rather than military tribunals.
"This verdict has proven that proceedings such as these can safely occur in the city I am proud to call home, as in other locations across our great nation," Holder said in a statement after a Manhattan jury Wednesday convicted 48-year-old Sulaiman Abu Ghaith of conspiring to kill Americans and aiding al-Qaida.
"It was appropriate that this defendant, who publicly rejoiced over the attacks on the World Trade Center, faced trial in the shadow of where those buildings once stood," Holder said.
Abu Ghaith, a Kuwaiti-born imam who married Osama bin Laden's eldest daughter about five years ago, is the highest-ranking al-Qaida figure brought to trial on U.S. soil since the Sept. 11, 2001, attacks.
Prosecutors said he played a leading role in the terror organization's post-9/11 propaganda videos, in which he and others gloated over the destruction.
He could get life in prison at sentencing Sept. 8.
Holder said the Obama administration never doubted the court system could administer swift justice. "It would be a good thing for the country if this case has the result of putting that political debate to rest," he said.
David Kelley, an attorney in private practice who served as U.S. attorney in Manhattan under President George W. Bush after successfully prosecuting 1993 World Trade Center bombing mastermind Ramzi Yousef, said the administration's approach was somewhat vindicated by a trial that showed "it can and should be, in appropriate circumstances, done in civil courts."
He said the trial should dispel the fears of big tribunal advocates, showing them they are "blowing a lot of hot air."
The conviction after six hours of deliberations came barely a year after Abu Ghaith was captured in Jordan and brought to New York, a transfer that drew some criticism that he was going to a civilian court.
In November 2009, Holder announced that the attacks' self-described creator -- Khalid Sheik Mohammed -- would be tried in Manhattan courts, a decision he reversed in April 2011 against rising political opposition, saying families of victims of the attacks deserved swift justice.
Now, Mohammed and four Guantanamo detainees are unlikely to be tried in military tribunals before next year.
U.S. Attorney Preet Bharara said he hopes the verdict brings some comfort to the families of al-Qaida victims.
"He was more than just Osama bin Laden's propaganda minister," Bharara said. "Within hours after the devastating 9/11 attacks, Abu Ghaith was using his position in al-Qaida's homicidal hierarchy to persuade others to pledge themselves to al-Qaida in the cause of murdering more Americans."
Abu Ghaith's lawyers had argued he was being prosecuted for his words and associations -- not his deeds -- and that there was no evidence tying him to terror plots that prosecutors suggested he knew about ahead of time.
After the verdict was read, Abu Ghaith smiled at a friend from Kuwait in the courtroom as he was led away.
His attorney, Stanley Cohen, vowed to appeal, complaining that the judge had pressured the jury for a verdict and had barred the defense from calling Mohammed as a witness. In a written statement, Mohammed had said Abu Ghaith had no military role in al-Qaida.
Cohen said prosecutors played to the worst fears of Americans with hundreds of mentions of al-Qaida and Sept. 11.
"For most New Yorkers and most people in this country, it is impossible to get beyond 9/11. It is impossible to get beyond the rhetoric and ignorance about the Middle East," he said.
In the trial's most dramatic testimony, Abu Ghaith described being summoned to a dark Afghanistan cave within hours of the destruction of the World Trade Center to confer with bin Laden, who told him: "We are the ones who did it."
Abu Ghaith testified that a worried bin Laden asked him how America would respond and he told him the U.S. would set out "to kill you and topple the state of the Taliban."
Abu Ghaith said it was during that meeting that he agreed to a request from bin Laden to speak on the widely circulated videos that were used to recruit new followers willing to go on suicide missions like 9/11, in which 19 men hijacked four airliners.
"The storm of airplanes will not stop," Abu Ghaith warned in an October 2001 video played for the jury.
Associated Press writer Jennifer Peltz in New York contributed to this report.
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