Aldawsari first came under suspicion in February 2011 when he ordered 10 bottles of concentrated phenol from a chemical company in North Carolina. The company became suspicious when the buyer was unable to provide a business or university address for delivery of the chemicals.
He later canceled the order. By then, agents of the Federal Bureau of Investigation had opened an inquiry.
What they found is that Aldawsari had been conducting research on the Internet and had downloaded a bombmaking recipe for trinitrophenol, or TNP.
In addition to phenol, the key ingredients for TNP are nitric acid and concentrated sulfuric acid. The agents confirmed that Aldawsari had already purchased 30 liters of nitric acid and three gallons of sulfuric acid.
That was more than enough to produce a bomb, explosives experts said.
During a search of his apartment, agents found a chemical set, flasks, a hazmat suit, a soldering kit, a battery tester, alarm clocks, and a stun gun. They said it appeared he’d purchased a strand of Christmas tree lights to wire a detonator.
According to court documents, Aldawsari used the Internet to obtain instructions to mix the chemicals into an explosive, as well as instructions to modify a cellphone into a remote detonation device.
One e-mail offered a simplified lesson in how to booby-trap a vehicle with common household materials. The lesson, the e-mail said in part, was directed especially to the brothers in America and Europe. It noted that “one operation in the land of infidels is equal to ten operations against occupying forces in the land of the Muslims.”
Agents also discovered that Aldawsari had sent himself e-mails listing potential targets for his planned attacks.