Roy said she had been so nervous about taking him on as an individual student that she worked out a code with her assistant: If she mentioned the name of a dead professor, her assistant would know it was time to call security. In another writing class, Cho submitted two profoundly violent and profane plays. Ian MacFarlane, a classmate who now works for America Online, posted the plays on the company’s Web site Tuesday, saying they had horrified the rest of the students. “When we read Cho’s plays, it was like something out of a nightmare,” MacFarlane wrote. “The plays had really twisted, macabre violence that used weapons I wouldn’t have even thought of.” As a result of them, MacFarlane added, “we students were talking to each other with serious worry about whether he could be a school shooter.” In one play, called “Richard McBeef,” Cho wrote of a teenage boy who accuses his stepfather of murdering the boy’s father and of trying to molest the boy himself. “I hate him,” the boy says of the stepfather in a copy of the play on the Web site. “Must kill Dick. Must kill Dick. Dick must die.” Though the level of anger was clear to those who knew Cho, there remains no indication of the precise motive for Monday’s events. “What was this kid thinking about? There are no indications,” said a federal law enforcement official who spoke on condition of anonymity. There were just the snippets of a lonely young life: prescription medicines, ominous words and two newly bought handguns, the first of which was purchased March 13. Cho was a 23-year-old senior, skinny and boyish-looking, his hair cut in a short, military-style fashion. He was a native of South Korea who grew up in Centreville, Va., a suburb of Washington, where his family owns a dry-cleaning business. He moved with his family to the United States at age 8, in 1992, according to federal immigration authorities, and was a legal permanent resident, not a citizen. Known as loner In the suite in Harper Hall where he lived with five other students, he was known as a loner, almost a stranger, amid a student body of 26,000. He ate his meals alone in a dining hall. Karan Grewal, 21, another student in the suite of rooms where he lived, recalled that when a candidate for student council visited the suite this year to pass out candy and ask for votes, Cho refused even to make eye contact. On Tuesday afternoon, investigators were examining a note Cho had left behind in his dorm room, a rambling and bitter list of the moral laxity he found among what he considered the more privileged students on campus. And new information emerged that might help explain a fateful two-hour delay by university officials in warning the campus of a gunman at large. According to search warrants and statements from the police, campus investigators had been busy pursuing what appears to have been a fruitless lead in the first of two shooting episodes Monday. After two people, Emily Jane Hilscher, a freshman, and Ryan Clark, the resident adviser who lived next door in a dormitory, were shot dead, the campus police filed a search warrant for the home of Karl D. Thornhill, who was described in Internet memorials as Hilscher’s boyfriend. According to the warrant, Hilscher’s roommate had told the police that Thornhill, a student at nearby Radford University, had guns at his town house. The roommate told the police that she had recently been at a shooting range with Thornhill, the affidavit said, leading the police to believe he might have been the gunman. But as they were questioning Thornhill, reports came in of widespread shooting at Norris Hall on the campus, making it clear that Thornhill was not the killer they were seeking. He was not arrested, although he continues to be an important witness in the case, the police said. Col. W. Steven Flaherty, the superintendent of the state police. State officials continued to defend the actions of the campus authorities. John Marshall, the Virginia secretary of public safety, said that Charles W. Steger, the president of Virginia Tech, and Chief Wendell Flinchum of the campus police “made the right decisions based on the best information that they had available at the time.” At an afternoon news briefing, Gov. Tim Kaine said Steger had asked him to appoint a committee to conduct a review that would examine the university’s response as well as issues such as how gun laws and policies affected the gunman’s actions. “There was certainly no evidence or no reason to think that there was anyone else (to suspect) at that particular point in time,” said Cho’s room searched After the shootings, the state police executed another search warrant, this time for Cho’s dormitory room. The warrant said a bomb threat against the engineering-school buildings was found near Cho’s body. The warrant mentioned two other bomb-threat notes against the campus received over the past three weeks. Cho had used two handguns, a 9 mm and a .22-caliber, to shoot dozens of rounds, leaving even those who survived with multiple bullet wounds, officials said. The guns were bought legally in March and April. Among the central questions is what prompted the gunman to move to Norris Hall, which contains engineering and other classrooms, where all but the first two killings took place. Authorities said Cho’s preparations, including chaining the doors, suggested premeditation, rather than a spontaneous event. Bodies were found in four classrooms and the stairwell of the building, Flaherty said. “You all have reported that this is the most horrific incident that’s occurred on a college campus in our country, and the scene certainly bore that out,” he said. “Personal effects were strewn about the entire second floor at Norris Hall. So it made it much more difficult for us to identify students and faculty members that were victims.” Officers also found several knives on Cho’s body. They first identified him by a driver’s license found in a backpack near the scene of the shootings, although it was not clear at first whether the backpack belonged to the gunman. But the name was checked against a visa application, and when a fingerprint on one of the weapons matched a print on the visa application, the authorities made a positive identification. The print matched another print left in the first shooting location. Investigators interviewed members of Cho’s family, but are said to have learned less than they hoped about his emotional state and recent activities. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! BLACKSBURG, Va. – Cho Seung-Hui rarely spoke to his own dormitory roommate. His teachers were so disturbed by some of his writing that they referred him to counseling. And when Cho finally and horrifyingly came to the world’s attention Monday, he did so after writing a note that bitterly lashed out at his fellow students for what he deemed their moral decline. “You caused me to do this,” an official quoted the note as saying. Cho’s eruption of violence, in which 32 victims and himself were killed on the Virginia Tech campus here in a rampage of gunfire, was never directly signaled by his actions or words, several of his acquaintances said Tuesday. But those acquaintances were frequently disturbed by his isolation from the world and his barely concealed anger. Joe Aust, who shared Room 2121 at Harper Hall with him, said he had spoken to Cho often, but had received only one-word replies. Later, Aust said, Cho stopped talking to him entirely. Aust would sometimes enter the room and find Cho sitting at his desk, staring into nothingness. “He was always really, really quiet and kind of weird, keeping to himself all the time,” said Aust, a 19-year-old sophomore, who, though finding Cho strange, had not thought him menacing. Yet there were signs that Cho’s behavior was more than just bizarre. Lucinda Roy, who taught Cho in a poetry workshop in the fall of 2005, said that in October of that year he submitted a piece of writing that was so disturbing that she contacted the campus police, counseling services, student affairs and officials in her department. She described the writing as a “veiled threat rather than something explicit.” University officials said he could be excused from the class unless she wanted to tutor him individually, which she agreed to do three times from October to December 2005. During those sessions, she said in an interview, he always wore sunglasses and a baseball cap pulled low. “He seemed to be crying behind his sunglasses,” she said.