The break in the arrest of Khalid Ali Aldawsari for attempted use of a weapon of mass destruction came when a shipping company and a chemical supplier called authorities to report the suspicious attempted purchase of a large quantity of Phenol, a chemical that can be used to make explosives.
Aldawsari, a 20-year-old college student from Saudi Arabia, had used his real name and contact numbers in trying to make the purchase. So, the FBI had a quick roadmap to the suspect. Searches of Aldawsari's apartment turned up chemicals, wiring, a hazmat suit and a journal detailing Aldawsari's desire to commit Jihad.
According to the FBI, Aldawsari researched a number of targets including hydro-electric dams.
There were also indications in the journal suggesting Aldawsari considered targeting the Dallas home of former President George W. Bush and at least three former U.S. soldiers who spent some time at the infamous Abu Ghraib prison in Iraq.
This was a fast-moving case. The FBI wasn't tipped until Feb. 1 and made the arrest just three weeks later. There is no indication that U.S. authorities knew anything about Aldawsari's alleged plans prior to receiving information from the chemical supplier and shipping company.
It is also interesting that he purchased most of his materials over the internet and the supplies were delivered directly to his apartment.
The investigation is still in its early stages, but it appears Aldawsari may be a true "lone wolf" - a would-be bomber who acted without direct help or contact with others. In his writings he did say 9/11 had changed him and he drew inspiration from Osama bin Laden.
Bob Orr is CBS News' justice and homeland security correspondent.