NOTE: the Associated Press originally reported that police believe the attack was rehearsed, but later retracted that information.
ROANOKE, Va. (AP) - Witnesses saw a suspicious male in the Virginia Tech classrooms where 30 people were shot dead and doors to the building were chained shut two days before the massacre, police said Friday.
The man, wearing a hooded sweat shirt, was seen about 10 a.m. on Saturday, April 14, in Norris Hall, said Virginia Tech police chief Wendell Flinchum in the first police news conference in months.
Seung Hui Cho, a mentally disturbed student, carried out the killings in Norris Hall after fatally shooting two others in the West Ambler Johnston dormitory on April 16.
Cho had chained shut all the exits from Norris Hall before the shootings, then shot himself to death as police broke through the chains and stormed inside the building.
State Police spokeswoman Corinne Geller said investigators don't know how long the doors to Norris Hall were chained shut in what might have been a practice run that Saturday.
But authorities have yet to find any evidence linking Cho to any of his victims on the Blacksburg campus.
Investigators have not located Cho's cell phone or the hard drive to his computers, which could answer that question and others, said Virginia State Police Superintendent Col. Steve Flaherty.
A report is expected later this month from a state panel named by Gov. Timothy M. Kaine that has looked into the shootings - the worst in modern U.S. history.
The panel's chairman, former State Police Superintendent Gerald Massengill, said the eight-member panel is still compiling the voluminous data it has gathered on Cho, who had a history of mental problems, as well as how the events unfolded and how the state and other agencies responded.
The panel is also still trying to figure out how it will brief the victims' families on the report's findings, he said.
"I don't know that we're going to give them a report or hand them a recommendation before it's made public, but we feel obligated to discuss the report as much as we can before" it's released, Massengill said.
The university also is doing its own reviews of safety and communications procedures that it expects to complete by late August.