More information was posted by the student's brother:
"I'm Jeff's brother and have a few additions to clarify the story. Jeff is an extremely travelled individual for his age, having made multiple prior trips to Europe and Africa (including Tanzania). He has a US passport and had the required visa for Tanzania. He is a well-dressed typical college student from rural Iowa. He was doing volunteer work for a school-sponsored program, which paid for his transportation to get there and left Jeff with few choices on how it was purchased. Jeff wanted to spend a few weeks vacationing in Europe after his time in Tanzania, but his school would not pay for his vacation travel. Therefore, the school bought the one-way ticket to Tanzania and Jeff bought a separate ticket leaving Tanzania to go to Europe, then eventually back home. He showed up to the airport hours before his flight, with plenty of documentation showing his summer plans. Somehow, the TSA had prior knowledge of his unusual itenerary and met him at the check-in counter for questioning. The TSA agent told him that they would need to further investigate his plans and he would have to wait atleast 24 hours to check back to see if he was cleared to fly."