This english article translates most of it
http://www.thelocal.se/20150209/station-guards-accused-of-violent-assault-on-boy-9
What it doesnt mention is how the security guard tried to choke the kid pretty much by holding for his mouth and nose. The two kids dont understand swedish and couldnt communicate with guards, runaways from social services home and were wanted by the social services/police because of that, its not just about dodging the train ticket etc. There is one thing holding kids until police arrives, and what was done in terms of unnecessary violence (this one sat on, beat his head on the ground, and almost choked a kid, while the other was more restrained, besides elbowing the other kid apparently), yeah the kid resisted big time, but it doesnt excuse doing this to a child at all
Police wasnt interested in hearing the witness accounts apparently (one of the guards reported one of the kids for assault btw lol, case was dropped instantly), and the guard only lost his job after alot of people reported this abuse. If it wasnt on camera nothing would happend.