"The way it’s been described to me is that we’re moving through classes, lots and lots of kids in the hall, and this group stops, hears this sound, people look down, some keep going, a few people register what it is and then turn it in to the front office," Fuller said.

The students described to administrators the what the person they believe dropped the magazine was wearing, but didn't have a name and couldn't otherwise describe the person's appearance.

Fuller said administrators conducted searches of some, but not all, backpacks during the lockdown based on the description provided by witnesses.

The school worked with law enforcement to create a dismissal plan with police supervision at all exits.

"We felt that it was important in order to run an organized, supervised dismissal that we were explicit about where students would be dismissed based on their mode of transportation," Fuller said. "The big thing we wanted to avoid was a big collection of unsupervised students upon dismissal so we were really strategic about one, two classrooms at a time so at any given moment, we never really had more than 25 students moving through the hall and exiting."

Students appeared calm as they left school grounds around noon.