The gunman who went on a rampage at Virginia Tech this week paused during the bloodbath to mail a package with photos of himself brandishing weapons and a video of a hateful, rambling
"You forced me into a corner and gave me only one option," Cho Seung-Hui, who massacred 32 people at the university on Monday, said in the video portion of the package that NBC News received on Wednesday and turned over to the FBI.
Fronting the MSNBC news Web site on Wednesday was a picture of the black-gloved gunman staring menacingly into the camera as he wielded the two handguns he apparently used in the shooting spree, the deadliest in modern U.S. history.
"Now you have blood on your hands that you will never wash off," the 23-year-old university student said without making clear to whom his remarks were directed.
The bizarre new twist added to an already chilling portrait of Cho, who after the killings took his own life on the sprawling rural campus in southwestern Virginia.
NBC said the package received at its New York headquarters bore a postal service time stamp that showed it was mailed sometime between Cho's killing of two people in a dormitory and his attack two hours later on a classroom building where he cut down 30 more people.
The package - containing what the network described as a "lengthy diatribe" - was turned over to authorities on Wednesday. NBC is cooperating fully with the authorities, an NBC spokeswoman said. CNBC is a unit of General Electric's NBC Universal.
"This may be a very new, critical component of this investigation," said Col. Steve Flaherty, superintendent of Virginia State Police. But he gave no details.
Among the material was a video showing Cho talking about his hatred of the rich, and a dense, 1,800-word diatribe laced with profanity and expressing a desire to get even, the network said.
Some photos Cho took of himself showed him posing with his weapons and clad in a dark vest in which he carried the ammunition clips he used to shoot his victims one by one. Witnesses said he stopped only to reload.
Other pictures showed him smiling into the camera.
NBC News President Steve Capus was quoted as saying while the package did not include any images of the shootings themselves, it did contain "vague references."
The disclosure followed word from university police that Cho had been accused of stalking women students and was taken to a psychiatric hospital in 2005 because of worries he was suicidal.
A Virginia court order issued at the time declared him "mentally ill" and said he presented "an imminent danger to self or others," ABC News reported.
Still grieving for the victims, both students and teachers had described a sullen loner whose creative writings for his English literature degree were so laced with violence and venom that they alarmed some people around him.
University Police Chief Wendell Flinchum said his officers confronted Cho in late 2005 after two women complained separately that he had harassed them in person, through phone calls and with instant messages. "I'm not saying they were threats; I'm saying they were annoying," Flinchum told a news conference at the campus.
After the second incident in December 2005, Cho's roommate warned police he might be suicidal, prompting them to issue a "temporary detention order" and send him to a nearby mental health facility for evaluation, Flinchum said.
Officials would not say how long Cho stayed at the facility, but roommates said he was gone for a couple of days. The women declined to file charges against Cho. Neither was among his victims on Monday, police said.
Despite encounters with the law and his past psychiatric treatment, Cho was able to legally purchase the two handguns he used in the attack. The shooting has rekindled debate over U.S. gun laws, the most lenient in the Western world.
News of Cho's past contacts with police and mental health specialists added to accounts of his erratic behavior, raising questions whether anyone could have picked up warning signs.
Cho immigrated from South Korea to the United States with his family in 1992 and was raised in Virginia outside Washington, D.C. Some South Korean officials feared a backlash against the large Korean community in the United States.