Wendell Flinchum, the chief of the Virginia Tech police department, said that it's common for university police to work with state-affiliated mental health facilities instead of on-campus counseling because it is easier to obtain a detention order.
"We normally go through access [appealing to the state's legal system for help] because they have the power to commit people if they need to be committed," Flinchum said at a press conference Wednesday morning.
Cho was taken to Carilion St. Albans Behavioral Health Center in Radford, Va., a private facility that can take 162 inpatients, according to court documents.
It's unclear whether Cho went to the hospital with police on his own or was taken there under protective custody, a possibility under the temporary detention order obtained by police.
One of the young women complained in November 2005 that Cho, then 21, was stalking her, but she declined to press legal charges against him. Police interviewed Cho for the first time and referred the case to the school's internal disciplinary board.
It's unclear whether any action was ever taken by the school, although Edward Spencer, a school vice president, said that it's not uncommon for a complaint never to reach a full hearing.
A second woman student, less than two weeks later, told authorities she received disturbing instant messages from Cho, and asked police to make sure there was "no further contact" from him.
Police spoke to Cho the next day. They say that shortly after, they received a call from an acquaintance of his, expressing concerns that he might be suicidal.
For a third time, police met with him. "Out of concern for Cho, officers asked him to speak to a counselor," Flinchum said. "He went voluntarily to the police department."
The student complaints that brought Cho to the attention of authorities came during the same time that creative writing professor Lucinda Roy went to administrators to voice her concern about violent themes in Cho's writing.
Roy told ABC News that Cho seemed "extraordinarily lonely -- the loneliest person I have ever met in my life."
While the school, citing privacy laws, did not conclusively say that school counselors had ever worked with Cho, they did say that a system for working with outside mental health agencies and local authorities is in place.
"Clearly, mental health professionals have a legal and moral responsibility," when a student presents a possible risk, said Christopher Flynn, head of the university's counseling center. "We have a duty to warn."
But Flynn also said that signs of trouble in Cho's behavior were not a clear indicator that action would follow. "It is very difficult to predict when what someone perceives as stalking, is stalking."
Seung Cho was quiet -- so quiet that some classmates of his say they never heard his voice in three years. His roommates reported he was distant and private, eating by himself night after night, and watching wrestling on TV.
Cho's roommates say he obsessively downloaded music from the Internet. One of his favorites was the song "Shine," by Collective Soul, which he played over and over
He was early to bed and early to rise, normally in bed by 9 p.m., and sometimes up by 5:30 the next morning. His roommates tell ABC News they would see him in the morning putting in his contact lenses, taking prescription medication and applying acne medicine to his face.