During the hours between the initial attack and his 30-victim killing spree, the Virginia Tech gunman mailed a large package containing a manifesto-like diatribe, videos, and photographs to NBC News. The package consisted of the 1,800-word document, 27 QuickTime videos, and 43 photographs.

The profanity-laced tirade allegedly written by shooter Cho Seung-Hui made only vague references to the shootings that had already unfolded and he would go on to commit. According to NBC News President Steve Capus, the document makes an indirect reference to Eric Harris and Dylan Klebold, the teens who killed 12 students and one teacher at Columbine High School in Colorado nearly eight years ago.

In the 10 combined minutes of video, Cho talks to the camera, mentioning “hedonism” and Christianity, as well as his hatred for the wealthy. Some clips show him leaning forward to turn off the camera, suggesting he produced them himself.

The photographs show a stern-faced Cho aiming handguns directly at the camera, wielding a knife, and also displaying hollow point bullets lined up on a table. According to Capus, the guns appear consistent with the guns reportedly used in the shootings.

On the morning of April 16, Cho opened fire in a Virginia Tech dorm and then, two hours later, shot up a building across campus, killing 32 people in the deadliest shooting rampage in U.S. history. He then committed suicide, bringing the death toll to 33.

The massacre took place at opposite sides of the 2,600-acre campus, beginning at about 7:15 a.m. at West Ambler Johnston, a co-ed dormitory that houses 895 people, and continuing at least two hours later at Norris Hall, an engineering building about a half-mile away.

Two people were killed in a dormitory room, and 31 others were killed in the engineering building, including the gunman, police said.

Previously, the deadliest campus shooting in U.S. history was a rampage that took place in 1966 at the University of Texas at Austin, where Charles Whitman climbed the clock tower and opened fire with a rifle from the 28th-floor observation deck. He killed 16 people before police shot him to death.