Still, Darkazanli has one consolation: the Germans have not arrested him or formally charged him with any crime. He remains a free man–just like two dozen or so other individuals who are subjects of unpublicized investigations by Germany’s Federal Criminal Police (BKA) into the origins of the September 11 plot. None has been charged with any criminal offense, although about 10 of them, Darkazanli not included, are classed as high-priority investigative targets. U.S. and European law enforcers claim to have documentary evidence linking some major suspects to one or more members of the Hamburg terrorist cell.

Why are they still running loose? So far Germany has made hardly any arrests in the case, aside from Mounir El Motassadeq, a Moroccan student who had power of attorney over one hijacker’s bank account. (Like Darkazanli, he has denied any involvement in terrorism.) Investigators are hamstrung by Germany’s strict civil-liberties protections. The law requires solid evidence before a suspect can be arrested, but it tightly limits the warrants and wiretaps that could produce such evidence.

Security officials have known for years that Hamburg was a haven for Islamic extremists. Even so, the local counterintelligence office had just one analyst watching them before September 11. Now the government has promised to field a whole new corps of counterspies and analysts against the Islamist threat, but German officials say they haven’t even been hired yet, let alone trained and deployed.

There was plenty of warning that trouble was brewing in Hamburg. The CIA inquired about Darkazanli after his name surfaced in the investigation of the 1998 U.S. Embassy bombings in Africa. When the Germans checked their files, they found he had already come to their attention for his ties to Islamic extremists. The authorities had nothing to charge him with, but after that they watched the city’s Islamists a little closer. In due course, they picked up hints of suspicious activity at 54 Marienstrasse–the apartment building where Mohamed Atta and his cell were hatching their plan. Investigators couldn’t get a warrant to wiretap the place; their case wasn’t strong enough. Now the government is revising the law to ease the gathering of evidence in terror inquiries. What that means for Darkazanli is another question.