I think these guys were "the evil doers" but not the evil masterminds. After the Bowie incident, the big guy split and they went on to do "stupid" $10 mil tricks. They may be "stupid" but they're not that stupid. They sacrificed themselves and that equates them to the suicide crew of 9-11.
They'll clam up just like Moussaoui and Reid and I wouldn't be surprised if they try to defend themselves. It's a suicide mission waiting to happen.
We have a piece missing by the way. How did they come up with the license plate in the first place?? The truck driver might have ID'd the vehicle at the rest stop but that's all he did. The clues from Alabama were insufficient. Someplace there's a tipster who is in "protective custody". Who??
Malvo's bragging about the shooting led them to match the print on the letter(Malvo's) to the one left at the Alabama shooting. The note and the voice indicated a foreigner. The print was on file with the INS in Seattle (they probably had to twist some arms to get the INS to cooperate). The INS incarcerated Malvo after a custody dispute between Malvo's mother and Muhammad, leading them to Muhammad. Muhammad's picture was on file in various jurisdictions, and probably with the FBI itself (since he'd been referred to them two or three times, most recently in July of this year). Witnesses in Alabama saw both Malvo and Muhammad when they ran from the scene, and most probably picked them out of a photo lineup.
A DMV search would turn up the registration/plate number for the car registered to Muhammad -- and there may also have been some witnesses who reported a New Jersey plate on a Caprice, but since it wasn't on a white van, it was ignored....