Seung Hui Cho might have tried a practice run two days before the April 16 massacre at Virginia Tech, chaining an entrance of the campus building where he would later walk from room to room, methodically killing 30 people before shooting himself, investigators said on Friday. A witness recalled seeing a man, who wore a hooded sweat shirt that obscured his face, lurking by the entrance to Norris Hall the morning of April 14, police said at a news conference. A second witness said one set of doors was briefly chained shut about the same time. Cho, 23, chained all three entrances during the attack two days later, slowing the police response. But Col W Steven Flaherty, the state police superintendent, said police cannot say with certainty that the person who chained the Norris Hall doors shut April 14 was Cho. “It would be speculation to suggest he was practicing on the door,” Flaherty said. Nearly four months after the deadliest shooting by an individual in US history — and despite conducting hundreds of interviews and collecting reams of evidence — investigators said they cannot explain Cho’s actions or motives or establish any links between him and his victims. “At this stage, we still have no evidence that answers the persistent question of why West Ambler Johnston . why Emily Hilscher,” Virginia Tech Police Chief Wendell Flinchum said. “We just don’t know.”
