One police officer reported dead and possibly another victim.
"This was a traffic stop on campus," Williams said. "It was not someone walking around firing shots."
A Virginia Tech alert described the suspected shooter as a white male wearing gray sweat pants, a gray hat with a neon green brim and a maroon hoodie, and carrying a backpack.
A Virginia Tech alert posted on the school's website said the suspect was last seen walking toward McComas Hall, which is the main gym on campus, about two blocks from Lane Stadium.