BLACKSBURG, Virginia (Reuters) - The gunman who massacred 32 people at Virginia Tech university was identified on Tuesday as a student from South Korea and a troubled loner whose behavior had sometimes alarmed those around him.
As students and teachers grieved at a tearful memorial service led by President George W. Bush, police said Cho Seung-Hui, 23, acted alone on Monday in carrying out the deadliest shooting rampage in modern U.S. history.
"Those whose lives were taken did nothing to deserve their fate. They were simply in the wrong place at the wrong time," Bush told a somber crowd that packed the university's 10,000-seat basketball arena to capacity.
Victims' friends and family members sobbed in each other's arms as speakers took the podium to comfort them. Many of the mourners wore maroon and orange, the school's colors.
The shooting spree on a sprawling rural campus in southwestern Virginia renewed heated debate over gun control in the United States. It prompted foreign critics to rail against a "gun culture" protected by the Western world's most lenient gun-control laws.
In Italy, the leftist Il Manifesto newspaper said the shooting was "as American as apple pie."
Though Cho's motive remained unclear, a chilling portrait of the gunman emerged as details of the bloodbath surfaced.
Cho, who immigrated to the United States 15 years ago and was raised in suburban Washington, D.C., killed himself after opening fire in classrooms where he apparently chained doors to prevent escape before cutting down his victims one by one. He used two guns and stopped only to reload.
He was also blamed for the shooting deaths of two other people two hours earlier at a dormitory on the campus.
Before the shooting spree, Cho left a rambling note lashing out at "rich kids," "debauchery" and "deceitful charlatans" on campus, the Chicago Tribune reported, citing investigative sources.
Steven Flaherty, superintendent of the Virginia state police, said there was no reason to suspect that Cho left a suicide note.
Lucinda Roy, an English professor, told CNN she became concerned after Cho's creative writing instructor came to her about disturbing passages he had written.
She said she took his writings to university officials, who said nothing could be done, and referred him to the university's counseling services.
Neighbors and roommates described Cho as quiet and withdrawn, but one former classmate said he was not surprised when he found out the shooter's identity.
"Looking back, he fit the exact stereotype of what one would typically think of as a 'school shooter' -- a loner, obsessed with violence, and serious personal problems," former classmate Ian MacFarlane wrote on an AOL blog site.
Cho who was studying English literature, wrote profanity-laced plays and had characters talk of pedophilia and attack each other with chainsaws, said MacFarlane, now an AOL employee.
The dead were found in at least four classrooms as well as a stairwell. The gunman was found sprawled among them, having taken his own life, police said.
Twelve students remained hospitalized in stable condition on Tuesday, officials said.
The campus, where there are more than 25,000 full-time students, reeled with shock and grief.
For Tuesday's memorial ceremony, an overflow crowd of several thousand filled most of the field in the neighboring football arena on a sunny spring day.
Many students said they felt exhausted and numb. Some shook with sobs as the hymn "Amazing Grace" played.
"We're just trying to cope with everything," said Jack Nicholson, 21, of Leonardtown, Maryland. "It's just been crazy."
University President Charles Steger and law enforcement officials on Monday defended their response to the shootings.
Many students have expressed anger that they were not warned of any danger until more than two hours after the first attack at a dormitory -- and then only in an e-mail from the university.
White House spokeswoman Dana Perino acknowledged that "there is going to be and there has been an ongoing national discussion and debate about gun control policy," but said the focus for now was on grieving families and the school.
More than 30,000 people die from gunshot wounds every year in the United States and there are more guns in private hands than in any other country. A powerful gun lobby and grass-roots support for gun ownership rights have largely thwarted attempts to tighten controls.
FACTBOX-Shootings at U.S. schools
FACTBOX-School shootings around the world
FACTBOX-Guns and gun ownership in the U.S.
Debate over U.S. gun violence