The police are required to establish probable cause before engaging in custodial interrogation. Much custodial interrogation relies on a fraudulent epistemic environment (FEE) in which the police knowingly use deception and dishonesty to gain an advantage over a suspect regarding a material issue, injuring the interests of the suspect. Probable cause, then, is a sort of evidentiary and epistemic standard that legally justifies the police’s use of deceptive and dishonest custodial interrogation tactics that are on par with fraud. However, there are both deontological and consequentialist considerations that show why the police’s use of an FEE is often unjustified. Accordingly, the paper argues that even if the use of an FEE is based on probable cause, there are other (non-epistemic) reasons to think evidence with probative value (such as a confession) should be excluded when derived from an FEE and there is no acute threat of harm to others.