Here is additional coverage after re-airing on July 19, 2014: This episode seems longer and more complete. Given the importance of the "fact v. fiction" problem in my own life (when I was substitute teaching) I'm a little baffled that I didn't recall seeing this episode before when I rewrote the notes below, as I didn't find the account above until later. Perhaps I missed part of it the first time, or more details have been added.
The case seems important because it illustrates the dangers of violent fantasy or media for someone who has a serious personality disorder (or "mental illness"). I presume that Twitchell got life without parole.
Note the Wikipedia attribution link of Edmonton race site. I visited the city (and Calgary and Banff) in September 1983. You can't see the Rockies from Edmonton; they are just out of sight. The climate is not as cold as you would think.
I'll consider ordering the book by Lilibeun as soon as I have a little more time to read it.