Hunt for the Killer

T1, E4: The brutal slaying of a respectable middle aged Vietnamese couple in Cabramatta is carried out amidst the stress of the Internal Affairs investigation. This time it's Malik in the hot seat. Whatever he says to I.A. will affect Crowley's future. Meantime, Malik and Koa try to work out who killed Mr and Mrs Ngo. Mrs Ngo was a difficult wilful woman who liked everything her way. Mr Ngo was a community minded man. Was the killer their own son? He stands to inherit the family wealth. The press reveal that several years back Mr Ngo was a witness of a gangland murder by the notorious Black Dragon street gang. Is this connected?