Seung-hui Cho, who according to authorities shot and killed 32 people at Virginia Tech Monday before turning the gun on himself, mailed photos, a letter and video clips of himself reciting an angry rant to NBC during a pause in his killing spree.
The multimedia manifesto included 27 video clips with 10 minutes worth of Cho's personal rantings and 43 still photos -- 11 of them showing Cho holding handguns.
A time stamp on the package showed that after Cho, 23, apparently shot the first two students, Emily Hilscher and Ryan Clark, around 7 a.m., he then went to the post office to mail it at 9:01 a.m. He then proceeded to Virginia Tech's Norris Hall, where he shot 30 people and then took his own life.
"You had 100 billion chances and ways to avoid today. But you decided to spill my blood," Cho said on the video in the package. "You forced me into a corner and gave me only one option. The decision was yours. Now you have blood on your hands that will never wash off."
In the video, Cho made a chilling confession.
"I didn't have to do this. I could have left, I could have fled, but no," he said. "I will no longer run. If not for me, for my children, for my brothers and sisters that you f--d. I did it for them."
Part of the package Cho sent to NBC aired on the network Wednesday night.
Included with the video clips was an 1,800-word diatribe in which he professed admiration for Columbine killers Dylan Klebold and Eric Harris.
Like Cho, they were loners who made videos that looked eerily similar to Cho's before going on a shooting spree at their high school.
In his letter, Cho wrote, "We martyrs like Eric and Dylan, will sacrifice our lives to … you thousand folds for what you apostles of sin have done to us."
Cho carried out his rampage on the same week as the Columbine murders were committed.
"Thanks to you, I die like Jesus Christ, who inspired generations of the weak and defenseless people," he said in the video.
In the package's 43 photos, Cho is smiling in two, an apparently unusual pose for him.
In the rest of the photos, Cho wears a vest, gripping two guns, likely the ones he used during the massacre.
The videos in the package contained rants similar to the letter police found in Cho's dorm room, in which he expressed his hatred for the rich.
"Did you want to inject as much misery in our lives as you can just because you can? You had everything you wanted. Your Mercedes wasn't enough, you brats," he said. "Your golden necklaces weren't enough, you snobs? Your trust fund wasn't enough?"
The postal clerk who served Cho told ABC News that she remembered him because he asked her to look up NBC's zip code.
She said that he came to the post office often, but she would not comment on his demeanor or his behavior.
"When the time came I did it, I had to," Cho said.