Germany yesterday signalled a new tough line on terror suspects by ordering a third trial on charges of abetting mass murder against a Moroccan engineering student who was close to the 9/11 suicide pilots.
Mounir el-Motassadeq, 32, is one of the few members of the Hamburg cell - which plotted and carried out the 2001 attacks on the World Trade Centre and the Pentagon - to have faced a court.
He was convicted last year of belonging to a terrorist organisation and given a seven-year jail sentence.
But it has proved difficult to sentence him for crimes directly linked to 9/11. Now the German supreme appeals court has ruled that the prosecutor should be given another chance to jail the student for the more serious charge.
"It was clear that Motassadeq knew his acquaintances from Hamburg were planning attacks with planes," said Judge Klaus Tolksdorff. A new trial, he ruled, should decide "the appropriate sentence for the act and his guilt" and would not need to hear fresh evidence or call new witnesses.
Motassadeq was a cheerful, seemingly well-integrated student who played in his local German football team where he was nicknamed Asparagus because of his spindly legs.
But after 9/11 German police found the credit card and email password of Mohammed Atta - the ringleader of the terror cell - in Motassadeq's apartment.
There was clear evidence that Motassadeq had paid the rent and electricity bills of the suicide pilots in their absence and transferred cash for their flying lessons. He had also countersigned the last will and testament of Mohammed Atta.
Motassadeq said all these acts were simply friendly gestures - one Muslim helping out others.
But his first trial, in 2003, was not convinced by this explanation and the diffident man, father of two children, was jailed for 15 years for abetting mass murder. German politicians hailed the conviction as a triumph, a sign that Germany was playing its part in helping the US crack down on terror networks.
But the sentence was squashed in March 2004 on the grounds that the US had refused to supply necessary testimony from al-Qaeda suspects held in American custody. Briefly, Motassadeq was a free man - and Germany was profoundly embarrassed.
The retrial in 2005 - this time with documents supplied by the US - found the student guilty of belonging to a terrorist organisation and jailed him for seven years. Motassadeq had admitted attending an Afghanistan training camp.
And at least one prosecution witness recalled him declaring his hatred of the United States. "Something big will happen," he reportedly said. "The Jews will burn and we will dance on their graves."
But the retrial still could not sentence him on murder conspiracy charges, with the judges ruling that only circumstantial evidence linked him to the 9/11 plot. Helping the plotters did not actually signify that he was privy to the secrets of the suicide cell.
Judge Tolksdorff from the supreme appeals court has now ruled that this was too generous towards Motassadeq. Enough evidence had been presented in the retrial, he said, to show that the defendant was aware that violence was going to be used against the passengers of commercial planes.
Even if Motassadeq did not know of a plan to smash into buildings in New York and Washington, it is said, the available evidence suggested he must have known that planes were about to be hijacked, deliberately endangering life.
If the new trial follows Judge Tolksdorff's reasoning, Motassadeq could be jailed for up to 15 years.