Screentime guru Tara Ward has some picks for your weekend:  Black Hands: The Bain family murders remains one of New Zealand's most controversial mysteries. New series Black Hands depicts the years leading up to the murders through the eyes of the victims and the accused (TVNZ1, Sunday night).  The Vow: a fascinating true crime documentary series that follows members who joined the self-improvement group NXIVM – whose leader, Keith Raniere, was convicted of sex trafficking and racketeering conspiracy, among other crimes – and reveals the emotional toll of unfolding events (Neon).   Anthony: In July 2005, black teenager Anthony Walker was murdered by two white men in an unprovoked racist attack in a Liverpool park. He was just 18 years old. This film, written by Jimmy McGovern, tells the story of how this talented young man's life might have turned out (Acorn TV). LISTEN TO AUDIO ABOVE