http://kaktuz.com/jkk/Columbine_Massacre_footage.html
I don't think its real because of the date, but I have no idea. I got it from another site, either way its pretty graphic and fucked up.
It made my stomach sick even watching it. Those were some fucked up kids.
Like I said, this video is very violent so if you getting offended easily don't watch it. I don't want to hear any fucking bitching and complaining if you choose to click on it.
There is also some nudity advertisements on the page.