During his trial, Aldawsari's attorneys acknowledged that their client had intent, but they argued that he never took the "substantial step" needed to convict him.
Defense attorney Dan Cogdell repeatedly berated Aldawsari as a "failure" and poor student who never came close to threatening anyone. Aldawsari did not testify at trial, but on Tuesday he told Walter he felt lonely and isolated from his family, friends and faith.
"I am sorry for these bad actions, but none of these bad actions did harm to the United States," Aldawsari told Walter.
Aldawsari wrote in his journal that he had been planning a terror attack in the U.S. for years, even before he came to the country on a scholarship, and that it was "time for jihad," according to court documents. He bemoaned the plight of Muslims and said he was influenced by Osama bin Laden's speeches.
Authorities said Aldawsari purchased bottles of sulfuric and nitric acids — chemicals that can be combined with phenol to create TNP.
Investigators say they were tipped to his online purchases by chemical company Carolina Biological Supply 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.
At his trial, prosecutors played recordings of a frustrated Aldawsari complaining to the supply company when his order was held up. He had allegedly told the company he wanted the phenol for research to develop a cleaning solution.
Aldawsari had transferred from Texas Tech in early 2011 to nearby South Plains College, where he was studying business. A Saudi industrial company was paying his tuition and living expenses in the U.S. The judge moved his trial to Amarillo, about 120 north of Lubbock.