I'm glad - I held off with getting an actual working link for this topic.
Yes, the footage is legitimate. Look at the December 11, 2012 watermark in the bottom left corner of the video.
[You must be registered and logged in to see this link.]Here's the link and I posted it to Mediafire this time.
NOTES:
1. Only 90 seconds long but, it's enough to make your skin crawl.
2. I apologize for the stupid Christmas music in the video, it was like that when I originally found it.
3. It's still on YouTube but, it got age-restricted.
4. Hardly anyone remembers this shooting - just 3 days later Sandy Hook happened, and this shooting became a blip in your memory.
5. The video ends as he goes up the stairs - right when his gun jammed.
6. Some 5-6 more people would've gotten shot, just because the shooter was an idiot, and he was too lazy to look up and down.