APTOPIX VaTech Shots Fired

A police officer secures the scene where a gunman killed a police officer and another person after a traffic stop Thursday, Dec. 8, 2011 on the campus of Virginia Tech, in Blacksburg, Va. The school said a police officer pulled someone over for a traffic stop and was shot and killed. The shooter ran toward a nearby parking lot, where a second person was found dead. (AP Photo/The Roanoke Times, Matt Gentry)