Embedded for three years with the notorious Noonan crime family in Manchester, England, the journalist Donal MacIntyre – the British answer to Geraldo Rivera – became a willing conduit for the outsize egos and self-serving confessions of its members. As a result, “A Very British Gangster” plays less like a documentary than an exposé of lowlife skulduggery. The movie attaches itself to the family’s smirking, openly gay boss, Dominic, between whose shaved dome and prosperous belly beats the heart of a monster. Though convicted of bank robbery, assault and hijacking and charged with kidnap and torture, this self-styled “social worker” (settling neighborhood disputes is a sideline) offers protection, security and banking services to grateful locals. The film’s director, however, has more colorful concerns. “There’s a hint of lavender about you,” he teases, eyeing Dominic’s permanent posse of young hoodlums and attention to grooming. The statement introduces the movie’s sole stab of tension as we ponder the likelihood of Mr. MacIntyre’s imminent demise.