BLACKSBURG, Va. — The 23-year-old who methodically pumped bullets into dozens of students and professors was a loner who emigrated from South Korea to the United States in 1992 with his family.
He spoke little in class, submitted disturbing writing assignments to professors and reportedly died with the phrase "Ismail Ax" inked in red on his arm.
Cho Seung-Hui, a senior at Virginia Tech, was identified Tuesday morning as the sole shooter in the campus slayings. Wielding two handguns, Cho killed 32 students and faculty members and injured nearly two dozen others.
The rampage ended when Cho shot himself fatally in the head with a wound so violent that investigators had trouble identifying him.
Law enforcement officials worked Tuesday to understand Cho's motives and paint a clearer picture of the young English major.
He was so isolated that few in the close-knit Korean community on campus knew him. Law enforcement agents were having difficulties learning about him, and English teachers and fellow students were troubled by some of his writings in classes.
"There was some concern about him," said Carolyn Rude, chairwoman of the university English department.
She said the department's chairwoman of creative writing, Lucinda Roy, had Cho in a class and described him as "troubled." He was referred to campus counseling on the basis of some of his writings, she said.
"Sometimes, in creative writing, people reveal things and you never know if it's creative or if they're describing things, if they're imagining things or just how real it might be," Rude said. "But we're all alert to not ignore things like this."
A fellow student, Stephanie Derry, told the campus newspaper that Cho's writings in a spring creative writing workshop included macabre slayings that featured bizarre weaponry.
"His writing, the plays, were really morbid and grotesque," Derry said.
"We made jokes around the class about his work, because it was just so fictional, so surreal, we just had to laugh," Derry said. "We had to laugh because it couldn't ever be real or truthful. I mean, who throws hammers or chainsaws around?"
When students questioned Cho, he just shrugged, Derry told the Collegiate Times.
"Cho was really, really quiet," Derry said. "I can't even remember one word he said the entire semester."
The Smoking Gun Web site posted a violent, profanity-laced screenplay that it said Cho wrote.
The short play describes a conversation between a 13-year-old boy and his stepfather, whom the boy accuses of being a pedophile. In the play, the stepfather, named Richard, lashes out at the boy, and the child's mother brandishes a chainsaw to protect her son.
In one scene, the boy throws darts at a picture of the stepfather's face, saying, "I hate him. Must kill Dick. Must kill Dick. Dick must die. . . . You don't think I can kill you, Dick?"
On the last page, the stepfather gives the boy "a deadly blow."
On campus, Cho appeared to keep to himself.
"No one knew him," said Young-Hwan Kim, president of the evangelical Korean Campus Crusade for Christ organization.
Kim said Cho rebuffed repeated invitations from the church group and declined to provide personal information.
"We had no contact throughout four years," Kim said. "It's amazing. We could not reach out to him."
Lee Seung-woo, president of the Korea Students Association, said he didn't know Cho either, though a friend was from the same hometown and knew Cho slightly.
A search warrant affidavit filed in Montgomery County, Va., circuit court said police found a "bomb threat note . . . directed at engineering school department buildings" near the bodies of Cho and some of his victims.
The Chicago Tribune reported that Cho left a "disturbing" note in his dorm room.
In the note, Cho railed against "rich kids," "debauchery" and "deceitful charms," the Tribune reported.
Cho came to the United States in 1992, when he was about 8 years old, with his family. He was a legal resident alien, a status that allowed him to legally purchase handguns.
Cho, like many of his victims, came to Virginia Tech from Fairfax County, Virginia, a suburb of Washington.
He graduated in 2003 from Westfield High School, where his only extracurricular activity was the science club his sophomore year. He didn't sit for a senior portrait.
Another Westfield High grad also has left a violent mark. In May 2006, Michael W. Kennedy fired more than 70 shots outside a Fairfax County police station, mortally wounding two officers.
Near his parents' townhouse in Centreville, Va., neighbors described the family as friendly, but few knew Cho.
Postal carrier Rod Wells said the family "always had a smile."
"It breaks my heart, because I know they're a nice family," Wells said. He said the family has lived in the house for about three years.
Neighbor Marshall Main said he was taking the trash out around 11 p.m. Monday when six police cars pulled up in front of the Chos' house. Two officers ran to the back of the home and the others went to the front door. A short time later, he said, "A lot of people streamed out of the house in the dark."
An unspent round of ammunition, appearing to come from a rifle, was recovered in the parking lot near the family's townhouse.
It was picked up by authorities, but they're not sure whether it's connected to the case, said Lt. R.J. Perez of the Fairfax County Police.
No one was at the family's home Tuesday, and relatives weren't returning phone calls. Cho's older sister, Sun-Kyung Cho, who attended Princeton University, served on an international internship with the State Department and wrote for the college newspaper.
Back in Blacksburg, students—especially those who saw Cho in class—continued to express disbelief about his actions.
"We always joked we were just waiting for him to do something, waiting to hear about something he did," Derry told the campus newspaper about her former classmate.
"But when I got the call it was Cho who had done this, I started crying, bawling."
(Mike Bold of the McClatchy Washington Bureau, Marcia Melton of the Fort Worth Star-Telegram and Jane Stancill of The (Raleigh) News & Observer contributed to this report. Zagaroli reported from Blacksburg, Va. Douglas reported from Centreville, Va. and Barrett reported from Washington.)