November 1, 1998-February 2001: 9/11 Hijacker Atta and Associates Are Monitored Some by US and Germany in Their Hamburg Apartment

Future 9/11 hijacker Mohamed Atta, al-Qaeda operatives Said Bahaji and Ramzi Bin al-Shibh, and others in the al-Qaeda Hamburg cell move into a four bedroom apartment at 54 Marienstrasse, in Hamburg, Germany, and some of them stay there until February 2001. Investigators will later believe this move marks the formation of the Hamburg al-Qaeda cell. [Los Angeles Times, 1/27/2002; New York Times, 9/10/2002] Up to six men at a time live at the apartment, including, at times, 9/11 hijacker Marwan Alshehhi and cell member Zakariya Essabar. Alshehhi moves out after the first month; it is unclear why. [New York Times, 9/15/2001] During the 28 months Atta’s name is on the apartment lease, 29 Middle Eastern or North African men register the apartment as their home address.
Surveillance of Bahaji – From the very beginning, the apartment is under surveillance by German intelligence, because of investigations into businessman Mamoun Darkazanli that connect to Bahaji. [Washington Post, 10/23/2001] The Germans also suspect connections between Bahaji and al-Qaeda operative Mohammed Haydar Zammar. [Los Angeles Times, 9/1/2002] Bahaji is directly monitored for at least part of 1998, but German officials will not disclose when the probe began or ends. This investigation is dropped for lack of evidence (see (Late 1998)). [Associated Press, 6/22/2002; Los Angeles Times, 9/1/2002] Bahaji moves out in July 1999 and gets married a few months later (see October 9, 1999). [Der Spiegel (Hamburg), 8/29/2011]
Surveillance of El Motassadeq – German intelligence monitors the apartment off and on for months, and wiretaps Mounir El Motassadeq, an associate of the apartment-mates who will later be convicted for assisting the 9/11 plot, but apparently it does not find any indication of suspicious activity (see August 29, 1998). [Chicago Tribune, 9/5/2002]
Surveillance of Zammar – Zammar, a talkative man who has trouble keeping secrets, does not live at the apartment, but he is a frequent visitor to the many late night meetings there. [Miller, Stone, and Mitchell, 2002, pp. 259-60; Los Angeles Times, 9/1/2002; Chicago Tribune, 9/5/2002] He even lives in the apartment for a time in February 1999 (see February 1999). Zammar is the focus of an investigation that began in 1997 and continues until early 2000 (see March 1997-Early 2000). Interest in monitoring him increases in late 1998 (see October 2, 1998).
Surveillance of Atta – The CIA also allegedly starts monitoring Atta in early 2000 while he is living at the apartment, and does not tell Germany of the surveillance (see January-May 2000). Atta leaves Germany to live in the US in June 2000 (see June 3, 2000).
No Direct German Surveillance of the Apartment? – Yet, even though people like Zammar who frequently phone and visit the apartment are monitored, German officials will later claim that the apartment itself is never bugged. An unnamed senior German security official will later say that some surveillance of associated people gives “the impression that the people living there were fanatical believers. At the BfV [Germany’s domestic intelligence agency], we had to decide whether to ask permission to place a wiretap on the line at 54 Marienstrasse itself. We discussed this every day.” But he will claim that they ultimately decide they will not be able to get legal permission for a wiretap because there is no evidence that the apartment’s occupants are breaking any laws. [Vanity Fair, 11/2004] This claim that the apartment was not directly monitored seems contradicted by reports that Bahaji was the target of a surveillance investigation when he was living in the Marienstrasse apartment in late 1998 (see (Late 1998)).
What Would More Surveillance Have Uncovered? – It will later be clear that investigators could have found evidence if they looked more thoroughly. For instance, one visitor will recall Atta and others discussing attacking the US. [Knight Ridder, 9/9/2002] 9/11 mastermind Khalid Shaikh Mohammed is in Hamburg several times in 1999 and comes to the apartment. However, although there is a $2 million reward for Mohammed since 1998, the US apparently fails to tell Germany what it knows about him (see 1999). [Newsweek, 9/4/2002; New York Times, 11/4/2002] 9/11 Hijacker Waleed Alshehri also apparently stays at the apartment “at times.” [Washington Post, 9/14/2001; Washington Post, 9/16/2001] Remarkably, shortly after 9/11, the German government will claim it knew little about the Hamburg al-Qaeda cell before 9/11, and nothing directed it towards the Marienstrasse apartment. [Daily Telegraph, 11/24/2001]