The concealed information test (CIT) assesses an examinee's recognition of a crime-relevant item using physiological measures. However, a guilty examinee not only recognizes the crime-relevant item but also conceals the recognition intentionally. In this study, we attempted to identify the effect of concealing the recognition on event-related potentials and autonomic responses. After committing a mock theft of two items, 30 participants received two CITs: one for an item that they had to conceal, and the other for an item that they had disclosed. N2, P3, heart rate, skin conductance, and cutaneous blood flow differed between crime-relevant and irrelevant items in both CITs. In contrast, late positive potential and respiration differed between crime-relevant and irrelevant items only when the examinee needed to conceal. The former measures appear to be related to orienting process, whereas the latter to controlled process related to concealment.