Who is Joey Zachariah from The Murderer's Daughters and what is their importance?

Joey Zachariah is Lulu and Merry's father. He was madly in love with his wife throughout their marriage, but after learning of his wife's many affairs, the couple separates. During their separation, Celeste steals one of Joey's paychecks, and when he confronts her, they end up in a fight in which Joey stabs her to death. He receives a life sentence for the murder but is later paroled.