A September 24, 2009 detention memorandum filed by the Justice Department alleged that Zazi had in his possession, "Jpeg images of nine pages of handwritten notes containing formulations and instructions regarding the manufacture and handling of different kinds of explosives...the same notes were transferred onto Zazi's laptop computer in June 2009...the notes contain among other explosives, the explosive Triacetone Triperoxide ("TATP") which is the explosive used in the 2005 London train bombings and intended to be used in the 2001 "shoe bomb" plot by Richard Reid."
The detention memo notes that Zazi flew from Pakistan to JFK on January 15, 2009 on Qatar Airlines flight 83. Within days of returning from Pakistan, Zazi moved to Aurora, Colorado. The detention memo alleges that Zazi transferred the bombmaking notes onto his laptop computer in June or July 2009 and that he conducted internet searches on how to safely handle hydrochloric acid.
The detention memorandum alleged that Zazi tested his explosive mixture in an Aurora, Colorado hotel suite that contained a stove in August and early September before departing for New York City. "On September 6 and 7, 2009 Zazi rented the same suite at the same hotel in Aurora where he stayed on August 28. The hotel surveillance camera captured Zazi checking in to the hotel at 2:32 p.m. on September 6. Subsequent FBI testing for explosives and chemical residue in the suite revealed the presence of acetone residue in the vent above the stove."
The detention memo notes that Zazi worked with as many as 3 other individuals, "On September 6 and 7, Zazi attempted to communicate on multiple occasions with another individual, each communication more urgent in tone than the last seeking to correct mixtures of ingredients to make explosives. Included in the communications were requests related to flour and ghee oil...Zazi repeatedly emphasized in the communications that he needed the answers right away."
The memo also alleged that Zazi conducted internet searches in the 11354 zip code in Queens looking for home improvement stores where he could buy Muriatic acid. Zazi traveled to New York on September 9, 2009 from the Denver area and arrived in New York on September 10, 2009. As he entered New York local police stopped him on the George Washington Bridge claiming the need to search his vehicle for drugs. Zazi became suspicious further when his car was towed by police who impounded his car. Zazi departed New York on September 12 and returned back home to Denver.