Investigators say Nafis traveled here in January for the purpose of carrying out a terrorist attack.
But an undercover investigation foiled that plan.
He was arrested after he allegedly tried to detonate what he thought was a one-thousand pound bomb, that he got from an FBI undercover agent.
Nafis is said to have had an overseas connection with al Qaeda, but it's not clear if he maintained those ties.
He now faces charges of attempting to use a weapon of mass destruction and attempting to provide material support to al Qaeda.
Nafis made an initial court appearance Wednesday.
His attorney, a public defender, declined to comment.
Southeast Missouri State University says Nafis was a student there, majoring in cybersecurity, from January to May of this year.