新闻背景：4月18日，美国全国广播公司（NBC）公布了枪击案嫌疑人赵承熙寄来的一个包裹的内容，其中包括赵承熙手写的23页宣言、43张照片和28份录像资料。凶手持枪或榔头摆出各种暴力姿势，加上充满威胁的言语，让尚未平静下来的美国人再次遭到巨大的心理冲击。

Video:Gunman kills 32 students in Virginia school

Bush expresses sympathy at Va. Tech convocation

Investigators said Thursday the disturbing video images of the student responsible for the worst shooting spree in U.S. history did not add much to their probe of what happened and why at Virginia Tech University on Monday. But the airing of gunman Cho Seung-hui's ranting video has angered relatives of the victims and some students. VOA National correspondent Jim Malone has the latest on the aftermath of the shooting tragedy from Washington.

Cho's video diatribe included angrytiradesagainst rich students and what he called theirdebaucheryand hedonistic needs.

The video contained pictures of Cho posing with two handguns. The video rant was oftenrambling, incoherent and at times profane, with Cho blaming others for his anger and frustration.

"You had a hundred billion ways to have avoided today, but you decided to spill my blood," said Cho Seung-hui. "You forced me into a corner and you gave me only one option, but the decision was yours. Now you have blood on your hands that will never wash off."

Police said the video offered little new from what they already had learned about Cho's troubled outlook on life and society.

Criminal profiler Pat Brown told CBS television that Cho's video provided insight into the mind of a mass killer.

"What he has shown in this video is that indeed, he is a psychopath, his very grandiose thinking, he is glorifying himself," said Brown. "He justifies what he does and this is for himself, not actually for other people."

Cho sent the video packet to NBC News in New York.

Investigators believe he mailed the package in between the two shooting incidents on Monday.

NBC decided to air excerpts of the video after turning over the material to law enforcement officials.

Virginia State Police Superintendent Steve Flaherty told a news conference at Virginia Tech he was disappointed NBC had decided to air the video.

"The victims and their families, the entire university campus and even the international community have certainly been afflicted by these horrific events and this horrific tragedy and this intense media attention," he said. "I am sorry that you were all exposed to these images."

Virginia Tech student Jonathan Brown was among those upset at seeing Cho's video confession.

"I think it is really sick that he would do something like that," he said.

NBC officials said they debated whether to air Cho's video diatribe, but in the end decided to go ahead.

NBC Today Show co-host Meredith Vieira defended the decision to air Cho's video on Thursday's program.

"What was contained in that rambling and hate-filled manifesto was not taken lightly, it was not made quickly and we understand that this is going to be seen as devastating to many people who lost loved ones in the shooting," she said.

Some criminal experts have expressed concern the Cho video could encourage similar acts of violence elsewhere. In the video, Cho referred to the two students responsible for the massacre at Columbine high school in Colorado in 1999 that killed 12 students and a teacher.

Several universities tightened security this week in the wake of the Virginia Tech shootings and several bomb scares were reported at colleges and universities around the country.

"The copy cat effect in school violence is alive and well, unfortunately, and it feeds on the attention that we give these school shootings," said Jack Levin, a criminologist who specializes in mass killers at Northeastern University in Boston.

In the wake of the shootings and now the disturbing video from the gunman, the Virginia Tech community and the rural town of Blacksburg are struggling to come to grips with the tragedy.

VOA's Brian Padden spoke to longtime local resident John Lemasters.

"We assumed the town was a safe place, that our university was a safe place," said Lemasters. "And that morning all of our assumptions were shattered."

Restaurant owner Ranae Gillie said the healing process would take time.

"We are all affiliated someway or another with the university," said Gillie. "When this horrific event happened, it affected each one of us all. And we are trying, in our own way, to do some sort of healing."

University officials said Thursday those students who died in Monday's shooting spree would be awarded their degrees posthumously during commencement exercises later this year.