He's not identifying a minority and labelling them criminals though, he's identifying other criminals that come from a particular minority.
All Romanians != Subset of Romanians in UK prisons.
He also mentions gangsters. It's quite within the bounds of what he's written that Romanian criminals in UK prisons that aren't gang members might also not want to associate too closely with the gangs.
not at all, but singling out a single ethnicity out of a massively mixed prison, quite is. particularly when it falls in the line of dailymail propaganda. or is racism racism only when against certain groups and not all?
He didn't single them out. He mentioned actually mentioned drug addicts first (which are most likely English) and then the Romanian Gangstars. I would imagine they either stood out in his mind or he happened to be in the same wing of the prison. If I met a Romanian Gangstar it would definitely stand out in my mind.
Also labelling criminals from Romania as Romanian is simply a statement of fact. If they were Japanese Yakuza or Chinese Triads I would expect him to call them Japanese and Chinese respectively.