A student paused Thursday evening at the memorial for the victims of the 2007 massacre at Virginia Tech. There was another vigil last night, following Thursday's killing of a campus police officer. Steve Helber/AP hide caption

itoggle caption Steve Helber/AP

The Virginia Tech campus is reeling after the confirmation of two deaths: a Virginia Tech police officer shot during a routine traffic stop and a second victim found at the university's Cage parking lot. Authorities are looking for the gunman. Matt Gentry/The Roanoke Times via AP hide caption

itoggle caption Matt Gentry/The Roanoke Times via AP

April 18, 2007: A bow -- in Virginia Tech's orange -- makes for a solemn marker on campus. Win McNamee/Getty Images hide caption

itoggle caption Win McNamee/Getty Images