Luqmaan Khan, 25, was arrested just before midnight on November 24.
The university has confirmed that Khan is an undergraduate student. He has been banned from all UD campuses while the investigation is underway, interim president Laura Carlson said in a statement.
Police say they were conducting a check at a park when they saw a white Toyota Tacoma, driven by Khan, in the park after hours.
He was taken into custody after police say he refused to exit his vehicle and resisted arrest.
Police searched the Tacoma and found several items inside, including a loaded handgun, extended magazines, body armor, a laptop and binoculars.
They also found a notebook, which allegedly contained notes on warfare techniques, assault plans, and a diagram of the University of Delaware Police Department.
According to police, the notebook also mentioned a member of the University of Delaware Police Department by name and included a drawing of the department's building with entry and exit points.
Federal authorities were contacted and searched his home, where they allegedly found a handgun equipped with an illegal "switch" to convert it into a machine gun.
Khan has been charged with several felony weapons charges, including possession of a large capacity magazine and carrying a concealed deadly weapon.
He has since been turned over to the FBI for additional criminal charges.