There were many reasons Feldis had no business being in that room, let alone co-opting the investigation. For one, the US Attorney’s Office wasn’t wired for audio and video recording of the interrogation. Nor did the building have proper security. Keyes wouldn’t be as intimidated, psychologically or physically, as he’d be at the FBI’s offices. These were all very real concerns. Feldis didn’t care. How about this liability? Police officers and FBI agents can, by law, lie to elicit a confession; prosecutors cannot.