ha ha ha . i think you are thinking about it too much. I really hope you are joking when you say the bbc are 'anti-white'.
No doubt the bbc, like any public organization has to be aware of race and try as much as possible to be representative of the reality of the society they are portraying without perpetuating old tired stereotypes that no longer hold true or starting new ones.
are you trying to say there should have been more black people in the gang to make it more realistic. if you are then even i can detect some slightly racist undertones. i don't think you are racist cos you care enough to ask rather than acting out any prejudice you might have.there are many all white gangs especially in the eastend.
i wish everyone was comfortable enough with peoples differences that your question would sound as silly as it would do if you replaced the words 'black youths' with 'black haired youths'.
you shouldn't even be thinking or caring about the issue of different races unfortunatley we are all classed as british now therfore we all get treated the same.we still have a long way to go before we are all colour blind. if YOU were, you wouldn't even have taken notice. this is why the bbc continue to question peoples preconceptions. it actually makes no difference if the crime was by a black or an asian .does it?