This is a compilation of reporting by ABC News and other organizations on the developing investigation into the massacre at Virginia Tech. This is a developing situation and the facts are subject to change.
Virginia Tech police have identified the shooter responsible for Monday's attack as Seung-hui Cho ("SOONG HEE CHO"). Cho apparently purchased the recovered murder weapons within the last two months -- a 9 mm Glock handgun on March 13 and a .22-caliber gun within the last week, sources tell ABC News.
So far 33 people are reported dead -- 32 victims plus the gunman, Cho, who killed himself -- making this the deadliest campus shooting in American history. As of now two victims have died from the shooting at West Ambler Johnston Hall; 30 from the attack on Norris Hall. University staff members are among the deceased. At least two classroom doors at Norris Hall were chained shut, according to university police.
At least 31 people have been identified in media reports as being among deceased victims -- five professors and 26 students. At least three foreign nationals are among the dead (two Indians and one Indonesian, based on media reports). See the "about victims" section below for names and more information.
A cryptic writing -- an inscription of "Ismail Ax" in red ink -- was found on Cho's arm. The same words, "Ismail Ax," were signed at the bottom of the disturbing note Cho left in his dorm room. (ABC News)
Two of Cho's roommates described coming home to police after a woman reported Cho had sent her repeated text messages and later followed her home. (CNN/"Anderson Cooper 360")
Cho's classmates were alarmed that he was taking inappropriate pictures of women under desks (New York Times)
Cho was portrayed by fellow students and teachers as an insecure loner who ate by himself night after night, watched TV wrestling shows alone and, when spoken to, had little to say. His one known passion was downloading music. (Los Angeles Times)
In recent weeks Cho's habits changed. He ventured out at night to the campus gym, lifting weights to beef up his skinny frame. He trimmed his hair into a military-style buzz cut. (LA Times)
Cho, a senior majoring in English, was normally in bed by 9 p.m. each night, up again by 7 a.m. But he began rising earlier, sometimes by 5:30 a.m., to put in his contact lenses, take prescription pills and apply acne medicine. (LA Times)
Two 22-year-old Virginia Tech seniors, Holly Huse and Christina Lilick, said in interviews with USA Today that they received a barrage of unwanted instant messages and phone calls from Cho last year. They said they became concerned enough by what they called "stalking" that they reported the matter to the resident advisers in their dorm. (USA Today)
Heather Haugh, the roommate of Emily Hilscher, one of the victims killed in West Ambler Johnston dormitory, had been off campus for the weekend. She walked up to the dorm shortly before 7:30 a.m., planning to meet her roommate to walk to chemistry class with her. But police pulled her aside at the door. That interview would shape the terrible day that followed. (LA Times)
Investigators told Haugh, 18, that her roommate had been shot. They began asking about Hilscher's romances. Haugh told them what she knew: Her roommate had spent the weekend on another college campus with her boyfriend, Karl Thornhill. (LA Times)