Frank was having a long-running affair with Stephen’s wife, Rose Marshbrook . He believed that by eliminating Stephen, he could "save" Rose and start a new life with her and her son, Oliver—a "fantasy" that Rose eventually dismissed during her own police interview.
Rose Marshbrook admits to making suspicious transactions and stealing money from the family firm. To avoid further charges, she agrees to testify against the company’s shady business dealings. the bay s02e06 720p
It is revealed that Andy didn't just move away; he remarried and fathered another child. Frank was having a long-running affair with Stephen’s