Federal agents secretly searched Aldawsari's apartment in Lubbock, Texas, twice in February 2011 and say they found almost everything needed to build a bomb, including chemicals, beakers, flasks, wiring, a hazmat suit and clocks, which he had bought online in the previous months.

Authorities say they were tipped to Aldawsari's online purchases by chemical company Carolina Biological Supply of Burlington, N.C., and shipping company Con-way Freight on Feb. 1, 2011. The chemical company reported a $435 suspicious purchase to the FBI, while the shipping company notified Lubbock police and the FBI because it appeared the order wasn't intended for commercial use.

Court records show that Aldawsari had successfully ordered 30 liters of nitric acid and three gallons of concentrated sulfuric acid in December 2010.

Aldawsari also kept a handwritten journal, in Arabic, in which he said he had been planning a terror attack in the U.S.