"The big question that investigators have to answer and answer quickly is whether this was a plot or was it really an isolated act," she adds.
Sen. Joseph Lieberman (I) of Connecticut has called the Fort Hood shootings a possible terrorist attack, citing statements Hasan had made to colleagues denouncing the US war in the Middle East and indications that he had turned to Islamic extremism.
Investigators are also reportedly looking into whether Hasan wired money to Pakistan in the days before the attack.
The wire transfer issue is potentially explosive, says McAvoy, because a common practice of the 9/11 terrorists was to live cheaply and wire all extra income back to their Al Qaeda handlers. The notion of an Army doctor getting paid nearly $100,000 a year while living in a squalid $350 apartment fits that profile, says McAvoy.
Reports about the money transfer come from Rep. Peter Hoestra (R) of Michigan, a member of the House Intelligence Committee, who told Fox News that some intelligence analysts are increasingly concerned about a terrorism connection. "They think it's a real lead," he said.