As tales of Cho Seung-Hui's worrisome behavior continued to surface Wednesday, a renowned poet and author who taught the 23-year-old suspected gunman called the notion that he was troubled "crap" and said he was downright "mean."

Nikki Giovanni was in San Francisco, California, getting ready to fly home to Blacksburg when she heard the news Monday that 32 students were killed in separate shooting incidents on the Virginia Tech campus.

"I knew when it happened that that's probably who it was," Giovanni said, referring to her former pupil. "I would have been shocked if it wasn't."

Though Giovanni, another professor, Cho's former roommates and a classmate all recall Cho behaving in a disturbing manner -- and authorities confirm he was investigated after being accused of stalking a woman -- there was nothing criminal about his demeanor. (Classmates called Cho "question mark kid")

In fact, university police Chief Wendell Flinchum said his department had no clue that Cho posed a threat to anyone.

"We're exploring all those things right now as we do our investigation to try and determine why and what triggers the incident. But we weren't aware of that before," Flinchum said.

The university and its police have been the target of criticism from students who felt they weren't adequately warned about Cho -- even after two people were killed in a dormitory early Monday morning.

Though police have linked a gun used in Norris Hall -- where 31 people, including Cho, died -- they have yet to say he is officially accused of the first shootings.

The university has defended its response to the first shooting, which police were reportedly still investigating when gunshots erupted in Norris Hall -- more than two hours after police were called to the dorm.

Flinchum said Wednesday that details gleaned from the investigation at the West Ambler Johnston dorm led to a decision among university officials and police that the campus did not need to be locked down.

"There is a lot of details we were providing to the administration and a decision was made based on that information," the chief said.

University President Charles Steger has said police believed the incident was "a domestic fight, perhaps a murder-suicide" that was contained to one dorm room.

Police cordoned off the 895-student dorm and all residents were told about the shooting as police looked for witnesses, Steger said.

"I don't think anyone could have predicted that another event was going to take place two hours later," Steger said.

'Something mean about this boy'
Though there was nothing criminal about Cho's behavior -- he easily passed a background check, according to the store owner who sold him one of the guns -- his actions did concern some students and faculty members. (Watch dealer recount selling weapon to Cho )

Cho's poetry was so intimidating -- and his behavior so menacing -- that Giovanni had him removed from her class in the fall of 2005, she said. Giovanni said the final straw came when two of her students quit attending her poetry sessions because of Cho.

"I was trying to find out, what am I doing wrong here?" Giovanni recalled thinking, but the students came to her during her office hours and explained, "He's taking photographs of us. We don't know what he's doing."

Giovanni went to the department's then-chairwoman, Lucinda Roy, and told her she wanted Cho out of her class, and Roy obliged.

"I was willing to resign before I was going to continue with him," Giovanni said. "There was something mean about this boy."

Giovanni said she's taught her share of oddballs in the past, but there was something malicious about Cho's behavior.

"I know we're talking about a troubled youngster and crap like that, but troubled youngsters get drunk and jump off buildings; troubled youngsters drink and drive," she said. "I've taught troubled youngsters. I've taught crazy people. It was the meanness that bothered me. It was a, really, mean streak."

Giovanni's account came Wednesday as Roy and Cho's former roommates shared stories about the resident alien from South Korea now accused of exacting the deadliest mass shooting in U.S. history.

Authorities also confirmed that Cho was investigated last year for stalking a woman in person and by e-mail.

Roy, who taught Cho one-on-one after removing him from Giovanni's class, recalled Cho exhibiting a palpable anger and secretly taking photographs of other students while holding the camera under his desk. (Watch the professor tell how her student frightened her )

His writings were so disturbing, she said, that she went to the police and university administrators for help.

"The threats seemed to be underneath the surface," she said. "They were not explicit and that was the difficulty the police had."

Ian McFarlane, who had class with Cho, said two plays written by Cho were so "twisted" that McFarlane and other students openly pondered "whether he could be a school shooter." (Read MacFarlane's blog and the two plays)

Cho's roommates, who asked to be identified only as Andy and John, had similar accounts. Andy recalled police coming to the dormitory to investigate Cho's involvement with a female students and when Andy told police that Cho had spoken of suicide, "they took him away to the counseling center for a night or two."

In retrospect, Cho had exhibited "big warning signs," Andy said. But he was so quiet, the roommate said, "he was just like a shadow." (Watch Cho's roommates describe his "crazy" behavior )

Authorities are still investigating whether Cho had any accomplices in planning or executing Monday's rampage, Flaherty said.

Cho, who moved to the United States at age 8, lived at the university's Harper Hall, Flinchum said.

"He was a loner, and we're having difficulty finding information about him," said Larry Hincker, associate vice president for university relations.