John Doe Number 2 looks an awful lot like Jose Padilla...............
John Doe #2 is identified in The Third Terrorist. His name is al Hussaini. He is ex-Iraqi Republican Guard and has their distinctive tatoo on his forearm.
The book details the witnesses who saw him get out of the Ryder truck seconds before the explosion, including one woman who was in the building and was one of the few survivors.
Her leg was amputated at the scene and because her "memory" could not be contaminated by news reports or talking with other people, she is a credible witness. She described Husseini to a tee.