The gunman in the Virginia Tech massacre was a sullen loner who alarmed professors and classmates with his violence-drenched creative writing and left a rambling note raging against women and rich kids.
A chilling picture emerged on Tuesday of Cho Seung-hui -- a 23-year-old senior majoring in English -- a day after the bloodbath that left 33 people dead, including Cho.
News reports said that he may have been taking medication for depression and that he was becoming increasingly violent and erratic.
Despite the many warning signs that came to light in the bloody aftermath, police and university officials offered no clues as to what set Cho off on his shooting rampage.
"He was a loner, and we're having difficulty finding information about him," school spokesman Larry Hincker said.
A student who attended Virginia Tech last fall provided obscenity and violence-laced screenplays that he said Cho wrote as part of a playwriting class they both took. One was about a fight between a stepson and his stepfather, and involved the throwing of hammers and attacks with a chainsaw. Another was about students fantasizing about stalking and killing a teacher who sexually molested them.
"When we read Cho's plays, it was like something out of a nightmare. The plays had really twisted, macabre violence that used weapons I wouldn't have even thought of," former classmate Ian MacFarlane wrote in a blog posted on an AOL Web site. He said he and other students "were talking to each other with serious worry about whether he could be a school shooter."
"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."
She said she did not know when he was referred for counseling, or what the outcome was.
Cho left a note that was found after the bloodbath.
A law enforcement official who read Cho's note described it on 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 the official said.