The money trail has been well established, and is quite familiar to the FBI that has “investigated” the 1995 Oklahoma City Bombing. (In fact, it is outlined in The Third Terrorist, the most comprehensive investigative report written by best-selling author Jayna Davis on the 1995 bombing that is available to the public)
The Norman Oklahoma Mosque has been on a federal watch list since 2002. And many have seen where Norman Oklahoma is one of the top terrorist recruitment centers in the US.
http://edition.cnn.com/2002/US/08/30/terror.hunt/