The incident took place around noon on Monday when a student at the White Hall complex in Midtown reported the sighting, said Sherri Hill, associate director of public relations.
The student called 911 and local, state and university police responded and school officials immediately notified students and faculty through the school's emergency communication system which sends a message through text, email or phone, said Hill.
They also posted the lockdown and shelter in place orders on Facebook and Twitter and on the university's homepage with a banner.
Responding police searched the campus and detained one man who "did not meet the criteria" of the person described, so they continued searching the campus, Hill said.
After a complete search by 2 p.m., it was determined that what the student thought she saw was actually an employee with a microphone stand, Hill added.
"The all clear has gone out and students are allowed back on campus and to leave their classrooms," she said.
Hill did not have information about the man who was detained.
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