That notification was disseminated via a text message sent from school officials to all students over an hour ago.
No one on campus has seen the individual -- it's someone off campus who made the phone call to police. At this point, there is no other information because the entire incident has developed as the result of that single, off-campus emergency call.
At this point the school is still on lockdown. Sirens have sounded that signal individuals to "stay put." Helicopters and other media personnel are circling the school.