as to the hideous photos, the news report state they were shared with a group including members of the public.
that word, including, suggests that other were not members of the public; so presumably, in the context, were police.
as to the location of the party, it is quite near to the address of the older sister, Bibaa, whose birthday it was.
she was a senior social worker in children's services, in a home counties area. not london.
where she lived and where the party took place is 71% non white british.
her sister, an artist and photographer, lived a little further away, in the next borough.