Thirty-three people at university dead, including gunman, in nation’s worst such incident.
However Steve Flaherty, the superintendent of the Virginia State Police, said while it was reasonable to assume that Cho was the shooter in both the first attack on a dormitory and the second, around two hours later at the university’s engineering department, that link was not yet definitive.
“There’s no evidence of any accomplice at either event, but we’re exploring the possibility,” he said.
Police said Cho was 23 and studying English literature. Authorities said he was a legal resident of the US but further details on his background were harder to find.
“He was a loner, and we’re having difficulty finding information about him,” Larry Hincker, a spokesman for the university, said.
The shootings are the worst in US history and have been condemned by, among others, George Bush, the US president, and the pope.
Bush was expected to attend a memorial service due to be held at the university later on Tuesday, the White House said.
The state’s governor Tim Kaine was flying back to Virginia from Tokyo for the ceremony.
Television images of terrified students and police dragging out bloody victims are likely to renew debate about America‘s gun laws.
The first shooting was reported to campus police at about 7:15am (1115 GMT) in West Ambler Johnston Hall, a dormitory housing around 900 students.
Two hours later, dozens of shots were fired a 800m away at Norris Hall, site of the science and engineering school.
‘Kept in the dark’
Many students were angry that they were not warned of any danger until more than two hours after the first attack at a dormitory – and then only in an e-mail from the university.
|Many students felt they should have received
more warning about the first shooting [AFP]
Andrew Capers Thompson, a 22-year-old graduate student, said: “We were kept in the dark a lot about exactly what was going on.”
Wendell Flinchum, the Virginia Tech campus police chief, said the first shooting had appeared to be “domestic in nature” so authorities did not feel that the campus needed to be closed.
“We had information that led us to believe that the building was secure and that the person had left the building,” Flinchum told reporters. “We acted on the best information we had at the time.”
He said the university had sent people to knock on doors to spread the word as well as sending the email, but it was difficult to reach everyone arriving on the campus.
Police said that over the past two weeks there had been bomb threats on the campus, which is attended by more than 25,000 full-time students, but had not established links between the bomb alerts and the shootings.
A memorial service and a candlelight vigil were held on Monday and flags will continue to hang at half-mast across the state.
It is the second time in less than a year that the Virginia Tech campus has been closed because of a shooting.
In August last year, opening day classes were cancelled and the campus closed when an escaped prisoner allegedly killed a hospital guard off campus and fled to the area around the Tech.