Assumptions • Conspirators and non-conspirators are linearly separable in the space spanned by local features (necessary for machine learning). • A conspirator is reluctant to mention to an out-sider topics related to crime. • Conspirators tend not to talk frequently with each other about irrelevant topics. • The leader of the conspiracy tries to minimize risk by restricting direct contacts. • A non-conspirator has no idea of who are conspirators, hence treats conspirators and non- conspirators equally.