BLACKSBURG, Va. – Virginia Tech students and supporters lifted thousands of candles to a sapphire sky to remember the 32 people killed by a campus gunman.
The vigil Tuesday evening testified to the unity on which the mountain campus prides itself. But in the hours after Cho Seung-Hui's rampage, it was obvious the close-knit school was a community of which he never felt a part.
• List of Victims in Virginia Tech Massacre
The gunman, who turned his gun on himself after carrying out the worst shooting massacre in modern U.S. history, was a sullen loner who left a rambling note raging against women and rich kids. News reports said that Cho, a 23-year-old senior majoring in English, may have been taking medication for depression and that he was becoming increasingly violent and erratic.
Professors and classmates were alarmed by his class writings — pages filled with twisted, violence-drenched writing.
In screenplays he wrote for a class last fall, characters throw hammers and attack with chainsaws, said a student who attended Virginia Tech last fall. In another, Cho concocted a tale of students who fantasize about stalking and killing a teacher who sexually molested them.
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"When we read Cho's plays, it was like something out of a nightmare," former classmate Ian MacFarlane, now an AOL employee, wrote in a blog posted on an AOL Web site.
"The plays had really twisted, macabre violence that used weapons I wouldn't have even thought of."
He said he and other students "were talking to each other with serious worry about whether he could be a school shooter."
Despite the many warning signs that came to light in the bloody aftermath, police and university officials offered no clues as to exactly what set Cho off on the deadliest shooting rampage in modern U.S. history.
"He was a loner, and we're having difficulty finding information about him," school spokesman Larry Hincker said.
"We always joked we were just waiting for him to do something, waiting to hear about something he did," said another classmate, Stephanie Derry. "But when I got the call it was Cho who had done this, I started crying, bawling."
Professor Carolyn Rude, chairwoman of the university's English department, said Cho's writing was so disturbing that he had been referred to the university's counseling service.
"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."
Click here to read FOXNews.com's interview with one campus professor
With classes canceled for the rest of the week, many students left town in a hurry, lugging pillows, sleeping bags and backpacks down the sidewalks.
On Tuesday night, thousands of Virginia Tech students, faculty and area residents poured into the center of campus to grieve together. Volunteers passed out thousands of candles in paper cups, donated from around the country. Then, as the flames flickered, speakers urged them to find solace in one another.
"We will move on from this. But it will take the strength of each other to do that," said Zenobia Hikes, vice president for student affairs. "We want the world to know we are Virginia Tech, we will recover, we will survive with your prayers."
As silence spread across the grassy bowl of the drill field, a pair of trumpets began to play taps. A few in the crowd began to sing Amazing Grace.
Afterward, students, some weeping, others holding each other for support, gathered around makeshift memorials, filling banners and plywood boards with messages belying their pain.
"Our hearts will be heavy, our tears will fall and our questions never really answered," one wrote.
"I think this is something that will take a while. It still hasn't hit a lot of people yet," said Amber McGee, a freshman from Wytheville, Va.
As this campus takes stock of the tragedy, it will be forced to confront the thinking that drove Cho's rage.
Cho — who arrived in the United States as boy from South Korea in 1992 and was raised in suburban Washington, D.C., where his parents worked at a dry cleaners — left a note that was found after the bloodbath.
A law enforcement official who read Cho's note described it Tuesday as a typed, eight-page rant against rich kids and religion. The official spoke on condition of anonymity because he was not authorized to speak to the media.
"You caused me to do this," the official quoted the note as saying.
Cho indicated in his letter that the end was near and that there was a deed to be done, the official said. He also expressed disappointment in his own religion, and made several references to Christianity, the official said.
The official said the letter was either found in Cho's dorm room or in his backpack. The backpack was found in the hallway of the classroom building where the shootings happened, and contained several rounds of ammunition, the official said.
Monday's rampage consisted of two attacks, more than two hours apart — first at a dormitory, where two people were killed, then inside a classroom building, where 31 people, including Cho, died. Two handguns — a 9 mm and a .22-caliber — were found in the classroom building.
Click here to read witness accounts of the grisly shootings
According to court papers, police found a "bomb threat" note — directed at engineering school buildings — near the victims in the classroom building. In the past three weeks, Virginia Tech was hit with two other bomb threats. Investigators have not connected those earlier threats to Cho.
Cho graduated from Westfield High School in Chantilly, Va., in 2003. His family lived in an off-white, two-story townhouse in Centreville, Va.
At least one of those killed in the rampage, Reema Samaha, graduated from Westfield High in 2006. But there was no immediate word from authorities on whether Cho knew the young woman and singled her out.
"He was very quiet, always by himself," neighbor Abdul Shash said. Shash said Cho spent a lot of his free time playing basketball and would not respond if someone greeted him.
Some classmates said that on the first day of a British literature class last year, the 30 or so students went around and introduced themselves. When it was Cho's turn, he didn't speak.
On the sign-in sheet where everyone else had written their names, Cho had written a question mark. "Is your name, `Question mark?'" classmate Julie Poole recalled the professor asking. The young man offered little response.
Cho spent much of that class sitting in the back of the room, wearing a hat and seldom participating. In a small department, Cho distinguished himself for being anonymous. "He didn't reach out to anyone. He never talked," Poole said.
"We just really knew him as the question mark kid," Poole said.
One law enforcement official said Cho's backpack contained a receipt for a March purchase of a Glock 9 mm pistol. Cho held a green card, meaning he was a legal, permanent resident. That meant he was eligible to buy a handgun unless he had been convicted of a felony.
Roanoke Firearms owner John Markell said his shop sold the Glock and a box of practice ammo to Cho 36 days ago for $571.
"He was a nice, clean-cut college kid. We won't sell a gun if we have any idea at all that a purchase is suspicious," Markell said.
Investigators stopped short of saying Cho carried out both attacks. But State Police ballistics tests showed one gun was used in both.
And two law enforcement officials, speaking on condition of anonymity because the information had not been announced, said Cho's fingerprints were on both guns. Their serial numbers had been filed off.
Gov. Tim Kaine said he will appoint a panel at the university's request to review authorities' handling of the disaster. Parents and students bitterly complained that the university should have locked down the campus immediately after the first burst of gunfire and did not do enough to warn people.
Kaine warned against making snap judgments and said he had "nothing but loathing" for those who take the tragedy and "make it their political hobby horse to ride."
At a Tuesday afternoon memorial service attended by President Bush and the first lady, Virginia Tech President Charles Steger received a 30-second standing ovation, despite the criticism of the school administration.
"As you draw closer to your families in the coming days, I ask you to reach out to those who ache for sons and daughters who are never coming home," Bush said.
Click here to read how a minister is helping Virginia Tech students cope
Click here to read about the hero professor who was killed trying to help students escape
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