Student gunman Cho Seung-hui sent video footage and photographs of himself to US TV network NBC News on the day he killed at least 30 people.
It is believed he posted the package during the interval between the two bouts of killing at Virginia Tech on Monday.
The images show him posing with weapons and ranting violently.
In one excerpt he tells the camera: "You had a hundred billion chances and ways to have avoided today."
The 23-year-old goes on to rage against "brats" and "snobs", and compares his own death to that of Jesus Christ.
The package also contained a 1,800-word letter, described by NBC News's Steve Capus as a "rambling, manifesto-like statement".
Teachers had expressed concerns about Cho Seung-hui because of his strange behaviour and disturbing writing, and he was admitted to a mental health unit in 2005.
The package did not arrive at NBC's headquarters until Wednesday because it was wrongly addressed.