THE gunman behind the Virginia Tech massacre killed two pupils who had attended his high school - where he was bullied, mocked over his shyness and told to "go back to China".
Cho Seung-Hui was taunted over his race during his time at Westfield High School.
The experience may have contributed to the mental instability, anger and persecution complex revealed in the killer's chilling videos, posted to an American broadcaster while Cho was in the midst of the worst campus shooting in US history.
It was also revealed that the violent poses Cho strikes in the "multi-media manifesto" in which he wields a hammer and a handgun might have been inspired by a controversial South Korean film. In the award- winning Oldboy, a businessman seeks revenge by going on a killing spree.
The former Westfield High pupils were among the 32 victims of Cho's rampage. Reema Samaha and Erin Peterson both completed their studies last year at the school in Chantilly, Virginia. Police said it is not clear whether Cho singled them out.
Chris Davids, a Virginia Tech student who graduated from high school with Cho in 2003, said that the killer almost never opened his mouth and would ignore attempts to strike up a conversation.
Mr Davids recalled that once, in English class, the teacher had the students read aloud and, when it was Cho's turn, he just looked down in silence. Finally, after the teacher threatened to give him a failing grade for participation, Cho started to read in a strange, deep voice that sounded "like he had something in his mouth," Mr Davids said.
"As soon as he started reading, the whole class started laughing and pointing and saying, 'Go back to China,' " Mr Davids said.
The killer's uncle, who still lives in Cho's native South Korea, said, as a child, the gunman worried his family by his reluctance to speak.
"We were concerned about him being too quiet, and encouraged him to talk more," said the man, who asked to be referred to only as Kim.
The classmates' and relatives' accounts add to the psychological portrait that is beginning to take shape, and could shed light on Cho's state of mind in the video rant he mailed to NBC in the middle of his rampage.
In the often-incoherent video, Cho, 23, portrays himself as persecuted and rants about "rich kids".
"Your Mercedes wasn't enough, you brats," says Cho, who moved to the United States in 1992 and whose parents work at a dry cleaners in suburban Washington. "Your golden necklaces weren't enough, you snobs. Your trust funds wasn't enough. Your vodka and cognac wasn't enough. All your debaucheries weren't enough. Those weren't enough to fulfil your hedonistic needs. You had everything."
Dressed in a black T-shirt, Cho is pictured swinging a hammer above his shoulder and holding a handgun to his temple. Similar images are among the most memorable scenes from Oldboy, which was released in Britain in 2004.
Cho posted a package containing 23 computer videos, 29 pictures and a 1,800-word statement to the broadcaster NBC.
In some clips, he compares himself to Jesus Christ and makes references to the 1999 Columbine High School killers.
Cho visited a post office in Blacksburg, Virginia, shortly after 9am on Monday morning, after he had already killed two students and about two hours before he embarked on the slaughter of 30 more students and professors at Virginia Tech.
In further footage released by NBC yesterday, Cho, wearing a black hooded top, said: "This is it. This is where it all ends. End of the road. What a life it was. Some life."
He added: "Do you think I wanted to do this? I didn't want to do this in a million years."
In another clip, Cho claimed he died to inspire generations of "weak and defenceless people".
Professor Paul Harrill, of Virginia Tech, said Cho may have been re-enacting scenes from the violent South Korean film. The images of Cho bear a startling resemblance to images from Oldboy.
The hammer is the signature weapon of the main character of the film and Cho is photographed wielding it in the same distinctive style.
The film, praised by Quentin Tarantino, was directed by Park Chan-Wook and won the grand prize at the 2004 Cannes Film Festival. Derek Malcolm, the leading British film critic, once described Oldboy as "an extraordinary film, it makes Kill Bill look like the proverbial vicarage tea party".
Other poses recorded by Cho resemble scenes created by the Hong Kong director John Woo, known for his violent action films such as Face Off.
When asked about similarities with Oldboy, Colonel Steve Flaherty, of the Virginia state police, said: "I have no knowledge of this movie and we have made no link that I am aware of."
Police said the videos had some marginal value, but suggested that they did not provide any new information for investigators. Officers also apologised for the fact that people around the world were able to view them.
"I just hate that a lot of people not used to seeing that type of image had to see it," said Mr Flaherty.
It was also announced yesterday that all the students among the 32 people murdered by Cho will be awarded posthumous degrees.
Man gave his life to save fellow student
A HEROIC graduate student was shot twice after distracting the Virginia Tech killer from a colleague who was playing dead.
Waleed Mohammed Shaalan was badly wounded and lay beside the other student, as Cho Seung-Hui returned twice to a classroom to search for signs of life.
Realising that the man beside him was alive and unhurt, the Egyptian-born student made a deliberate movement to draw Cho's attention away from the survivor.
Cho executed Mr Shaalan with a shot to the head.
Randy Dymond, a civil engineering professor, said the other man believed Mr Shaalan "purposefully distracted Cho to save him".
Mr Shaalan, the married father of a 15-month-old son, had gone to United States last year to study for a PhD in civil engineering.
Mr Shaalan's father, a retired government official, said his son spoke to the family only hours before the massacre.
"The night before his death, he insisted on talking with us through a webcam to see our faces," the father told Cairo's daily newspaper Al-Masry el-Youm. He told his family on Sunday that he planned to come home in May to take his wife and son back to the US.
Fahad Pasha, who was Mr Shaalan's room-mate at the university, described him as "the nicest guy I ever knew".
• THE decision by NBC to air some of the video and pictures sent by Virginia Tech gunman Cho Seung-Hui sparked a backlash from victims' families yesterday.
Some "very upset" relatives cancelled plans to appear on the network's Today show.
Matt Lauer, the programme's host, defended the broadcaster.
"We've made the decision because by showing some of this material, perhaps it will make us understand or answer the question why, why did it happen," he said.
But he added that NBC feels strongly that "this is not some kind of video that we need to run in some kind of endless loop".