"Let's see, there he is right there. Mohammad, Khalid."

Back in the 1980s, all Chowan students — and that would have included Khalid Sheikh Mohammed — were obliged to study Christianity extensively. That meant prayers, singing and biblical instruction in addition to regular classes. It was an odd requirement for the son of an imam who had been a member of an Islamic group, Muslim Brotherhood, since he was 16.

Dr. Garth Faile was Mohammed’s freshman chemistry teacher. He’s a soft-spoken man from Alabama who has been teaching at Chowan for nearly 40 years. Faile, wearing a tie that shows the elements in the periodic table, pulls out an old blue grade book and finds his former student…

Faile has taught chemistry in the same classroom for almost 40 years. It is stark and white but for the eight rows of desks all bolted to the floor. The professor walks about halfway down the first row and puts his hand on the chair. “He sat about here,” he said, of Khalid Sheikh Mohammed. Aside from remembering where he sat, Faile says there was nothing that stood out about Mohammed — though he did earn one of one highest grades in the class.

“What he had in mind then, as opposed to now, I don’t know,” Faile says.