BLACKSBURG, Va. — The gunman in the Virginia Tech massacre was a sullen loner who alarmed professors and classmates with his twisted, violence-drenched creative writing and left a rambling note raging against women and rich kids.

A chilling picture emerged 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, who killed himself as police closed in.

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 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.

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, now an AOL employee, 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. Rude refused to release any of his writings or his grades, citing privacy laws. The counseling service refused to comment.