Virginia's governor has named an independent panel to investigate a university massacre by a mentally ill student, as the grieving town held the first funeral for one of the dead.
Governor Tim Kaine's announcement came as Virginia Tech university officials faced questions over whether the killer, a student with a history of mental problems and stalking women, should have been allowed to remain in school.
Cho Seung-Hui, 23, a Virginia Tech senior, went on the rampage in Blacksburg on Monday mowing down 33 teachers and students with two recently bought handguns, according to police. It later emerged he had been identified as mentally ill.
In a video diatribe sent to a US television network, a clearly unbalanced Cho brandished the murder weapons, painted himself as a long-suffering martyr and compared himself to Jesus Christ.
Kaine said the panel would seek to discover "everything we know" about Cho, including his dealings with the mental health system and the type of treatment he received.
It will include former high-ranking police and security officials and a psychiatrist and state education official, and will aim to answer the questions: "What were the warning signs? Who was warned? What was done?" he said.
The panel will investigate the two-and-half-hour gap between the first shooting Monday morning, in which two people were killed, and Cho's rampage in a classroom building where he killed 30 other people.
It will also delve into the police and emergency medical responses to the shootings.
Shortly before Kaine's announcement, Virginia Tech vice president Ed Spencer cautioned against trying to affix blame. "I think about the seductive temptation to blame and I hope that none of us get into that," he said.
The panel will be headed by Gerald Massengill, a former Virginia police chief, and will include Tom Ridge, a former head of the US Department of Homeland Security, plus a veteran Federal Bureau of Investigation (FBI) official.
Cho has been described as a sullen loner by students, teachers and his roommates and his violent writings and intimidating manner raised alarm bells among some of his professors long before the attacks.
He was committed to a mental institution in December 2005 after one of two stalking incidents involving female students but was released the next day for outpatient treatment after he was deemed not to be a danger to others.
Chris Flynn of the university counseling center said the decision to commit Cho to a mental health facility was taken by a Virginia district court and there are strict privacy rules about what information can be shared.
"Who gets notified under that court order and who is notified is determined by (health privacy) regulations and not the university," he said. "We would not be the providers of mandatory counseling in this instance."
Grieving families, meanwhile, began claiming the victims' bodies at the state medical examiner's office in nearby Roanoke while the first funeral took place.
The university's tight-knit Indonesian community gathered at McCoy Funeral Home to honor Partahi "Mora" Lumbantoruan, an engineering doctoral student from Sumatra.
Police superintendent Colonel Steve Flaherty told reporters, meanwhile, the chilling manifesto sent by Cho to NBC News had been of only "marginal value" to the investigation.
He said he could not confirm that Cho personally had mailed the package to NBC on Monday.
The package was postmarked 9:01 am, one hour and 45 minutes after the first two victims were killed in a campus dormitory and about 30 to 40 minutes before the second attack, during which 30 people died and Cho committed suicide.
Flaherty thanked NBC for its cooperation with the authorities but lamented that the network chose to air excerpts from the manifesto, which contained 27 short videos, 43 photographs and an 1,800-word document.
"We're rather disappointed in the editorial decision to broadcast these disturbing images," he said. Suhail Samaha, a cousin of Reema Samaha, one of the victims, said he "would have rather not seen it." "It just didn't serve any purpose except to make me angry," he said.
NBC defended its decision to release the video. Along with other networks including CNN, it later pledged to reduce the amount of air time devoted to the footage however, US media reported.
"We have covered this story -- and our unique role in it -- with extreme sensitivity, underscored by our devoted efforts to remember and honor the victims and heroes of this tragic incident," NBC broadcaster said in a statement.