I really don’t think there was much fraud at this level.
The fraud occurred at the mortgage broker level. The brokerages who packaged and sold these loans may have participated by selling paper they knew was bad. However, Lehmann and AIG were purchasers of these securities, not packagers.
If the FBI wanted to investigate somebody, they should check into that loose cannon at CitiCorp who was cooking up SIVs in the back room with little regard to anything but his own bonus.
the fraud was done by carter (cra) and clinton (reno) by forcing loans to be made to unqualified buyers - all else is distraction