 It is revealed that while at Duke University, he had met two killers Casanova and The Gentleman Caller, who later become the villains in "Kiss the Girls", and started killing along with them before heading off on his own.Some time during his life, his met his unknown wife, married her and had a couple of children.While in the FBI, Craig started looking across the United States for other known killers, two of whom were the Audience Killer and the Wolf, two villains who later appear in other novels as villains to Alex Cross.