NBC played excerpts from the video on its evening newscast. The gunman is seen talking angrily in the video in what the network described as a incoherent manifesto.

"You had a hundred billion chances and ways to have avoided today, but you decided to spill my blood. 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," he said.

Some of the pictures released by NBC showed Cho brandishing guns. One picture showed him holding two guns, one in each hand in a firing pose. In another picture, Cho points the barrel of the gun directly at the camera.

NBC said it received the package Wednesday, but it contained a stamp indicating it was mailed about an hour and 45 minutes after he first opened fire on the university campus, killing two students.

Many of Cho's comments were laced with profanity and were spoken in an angry monotone voice. "I didn't have to do it. I could have left. I could have fled. But now I am no longer running. If not for me, for my children and my brothers and sisters that you (expletive). I did it for them," he was heard saying.

The pictures and video are the latest in a series of disclosures about the gunman that have sufaced since the killing.

It was reported that he had two stalking complaints filed against him in 2005 and later a magistrate signed an order after an initial evaluation that found probable cause that Cho was a danger to himself or others as a result of mental illness.

NBC said it turned over the package to the FBI. The network released excerpts from the package just before the FBI released a statement about it.

Police said it was not clear when the recordings were made.