Conventional interrogation is ineffective because the treating physician thinks that DeSalvo suffers from a split personality: he has two identities that are unaware of each other. His "normal" personality fabricates memories in place of the memories of murder committed by the "strangler" personality. The treating physician thinks that DeSalvo could be made to confront the facts but that the shock risks putting him in a catatonic state. Bottomly expresses the opinion that catatonia would be the second-best thing to a conviction.