The subjects included males between the ages of 25 and 45, arrested on suspicion of larceny, drug offenses, and burglary. All polygraph outcomes were confirmed by the subject's own confession or by the judicial decision in the trial. Each stimulus was presented on a CRT screen for visual ERP or through headphones for audio ERP. The signals were sampled for 1000 msec. Baseline- to-peak amplitudes of late positive components were digitized and analyzed. The data indicate that ERPS are sensitive to detecting information using electrophysiological manifestations of information processing brain activity. The visual ERP is superior to the audio ERP because of smooth elimination of noise. However, the ERP method is limited in that visual inspection of ERP waveforms often reveals differences between presented items regarding details of a crime. The ERP method is inferior to standard polygraphs and should be considered a subjective measure by legal standards. 2 tables, 10 figures, and 14 references