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.
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.