The Main Street post office where Cho is believed to have mailed his package is small and dingy. There are no security cameras; just a small counter where people can fill in envelopes before heading to the window. An older postal clerk sorts letters early each morning, slipping them in rows of post office boxes.
Cho apparently arrived there half an hour after it opened, handing the clerk his envelope. The walk to Norris Hall is less than 15 minutes through the main gates and past the chapel.
-- By Deborah Feyerick, CNN Correspondent