You are throwing together two very different discussions that are going on in this thread.
Earlier someone said this story was only reported because it was refugees doing the crime and the media had an agenda with this. That is simply untrue in this case, because we have coverage from before the suspects were identified or pictures even released. Most probably it was reported upon internationally because of earlier incidents taking place in the Berlin metro - which were not refugee related.
Now the suspects are identified as refugees, of course the discussion then goes towards how to deal with these people - the ones committing the crime - and there are different opinions about that. Their refugee status holds relevance here, because they were given help and repaid that with doing a very serious crime.
Then in that case the suspects are probably German, as would be assumed when reading a German newspaper about an event in Germany. Nationality is one of the most normal things to mention in news reports when there are foreigners involved. This happens all the time without any xenophobic agenda.
And my German is a bit rusty, but doesn't that linked report talk about how the victim was from Poland? Which is very normal to report, otherwise we would assume he was German, being that the crime took place in Germany, but it is mentioned because it is something else.
This stuff is just basic journalism and nothing strange at all.