It's been published last year beginning of Jan 2018.
There's an archived halfchan thread at
www.webcitation.org/6wHb0ZAwx
and an imgur thread with some more images:
imgur.com/a/37tfd
Reddit had a thread around the same time
www.reddit.com/r/The_Donald/comments/7oqspo/happening_anon_posted_evidence_of_baltimore_riots/