Well if the FBI sends one of their "informants" to mix the chemicals and build the bombs for them as they've done in the past, well of course then they know it WILL happen.
...“The notion of probability of a WMD attack being low or high is a moot point because we know the probability is 100 percent,” Majidi says. “We’ve seen this in the past, and we will see it in the future. There is going to be an attack using chemical, biological or radiological material.”
Even a WMD attack that does not kill a great number of people would have a crushing psychological impact.
“A singular lone wolf individual can do things in the dark of the night with access to a laboratory with low quantities of material and could hurt a few people but create a devastating effect on the American psyche,” Majidi says.
As described by Majidi, who was previously the chemistry division leader at Los Alamos National Laboratory, the WMD Directorate was established in 2006 to coordinate all elements of the FBI that deal with WMD cases.
Regarding a subject that is full of hype and misinformation, it is rare for an official who is an expert in the field and has full access to current classified information to talk about it for publication.
Majidi says the kind of threat that keeps him awake at night is one from a lone wolf. That’s because the FBI, along with the CIA and foreign partners, has developed a number of ways to detect plots by al-Qaida and other foreign terrorists. Besides intercepting their communications and infiltrating their organizations, the FBI gets reports when people purchase materials that could be used in a WMD attack. These techniques are known as trip wires...