Who is Kenneth Voigt from 'I' Is for Innocent and what is their importance?

Kenneth Voigt was Isabelle Barney's second husband. Their divorce was not Kenneth's idea, and he comtinues to be as deeply in love with her after their marriage as he was throughout. Kenneth was heartbroken when Isabelle married David Barney. When Isabelle is killed, Kenneth is one of the first to point fingers at David. Six years later, he brings a wrongful death case against David, claiming he wants his daughter Shelby to inherit all of Isabelle's money.