January-May 2000: 9/11 hijacker Atta is put under surveillance by the CIA while living in Germany. [Berliner Zeitung, 9/24/01] He is "reportedly observed buying large quantities of chemicals in Frankfurt, apparently for the production of explosives [and/or] for biological warfare. The US agents reported to have trailed Atta are said to have failed to inform the German authorities about their investigation. The disclosure that Atta was being trailed by police long before 11 September raises the question why the attacks could not have been prevented with the man's arrest." [Observer, 9/30/01] A German newspaper adds that Atta was still able to get a visa into the US on May 18. The surveillance stopped when he left for the US at the start of June. But "experts believe that the suspect remained under surveillance in the United States." [Berliner Zeitung, 9/24/01] This correlates with a Newsweek claim that US officials knew Atta was a "known [associate] of Islamic terrorists well before [9/11]." [Newsweek, 9/20/01] However, a Congressional inquiry later reports that the US "intelligence community possessed no intelligence or law enforcement information linking 16 of the 19 hijackers [including Atta] to terrorism or terrorist groups." [Senate Intelligence Committee, 9/20/02] How did the CIA know to start surveilling Atta in January? Could they have tracked Ramzi bin al-Shibh from a meeting in Malaysia (see January 5-8, 2000) back to the Hamburg apartment he was sharing with Atta (see November 1, 1998)?