Not Hacker News.
Also, the video is extremely interesting in its own right.
The best way to know if something is off topic, and indeed the best reason not to post off topic stuff, is if you think the community will spend more time debating whether the article is on or off topic than the article itself.
Although, I wouldn't say it if I could just downvote it.
RTFG
I think most people agree that people who kill someone ought to get locked up, even if it isn't convenient.