The subreddit is already banned, but archive has screen shots (https://archive.ph/https://www.reddit.com/r/robert_crimo_project/) and it was indeed created one month ago according to JS:
The original post had 780 comments before Reddit banned the sub - none of the comments are archived there.
Wayback has one capture from 4 minutes after the original post was created on may 17:
And then 4 captures from over night, again none appear to have captured all the 750 comments, but the earliest one caught some:
Link to a blog with photos and videos, posted in the reddit thread, still up:
https://robert-crimo-archive-footage-files.blogspot.com/
Twitter account temp restricted: https://twitter.com/b74776838
Some archived screenshots, account created May 17:
i live in illinois. people all know about the violence in chicago. but it tends to stay there and does NOT go past niles. shit like this just doesnt happen in the suburbs and all. was quite a shock tbh. highland park is a very very safe and area with nice people. i go there all the time to chill out and drink some coffee. has that small town illinois feeling!