 The arrows depict relationships of influence between variables. Whether Sally Clark’s sons, call them \(A\) and \(B\), died by SIDS or murder (A.cause and B.cause) influences whether signs of disease (A.disease and B.disease) and bruising (A.bruising and B.bruising) were present. Since son \(A\) died first, whether \(A\) was murdered or died by SIDS (A.cause) influences how son \(B\) died (B.cause). How the sons died determines how many sons were murdered (No.murdered), and how many sons were murdered decides whether Sally Clark is guilty (Guilty).