Mock crime application of the Complex Trial Protocol (CTP) P300-based concealed information test


  • This research was supported by the Department of Defense Polygraph Institute Grants DoDPI98-P-0001 and DoDPI04-P-0002 awarded to J.P.R.

Address correspondence to: Michael R. Winograd, Department of Psychology, Northwestern University, 2021 Sheridan Rd., Evanston, IL, 60208. E-mail:


The Complex Trial Protocol (CTP), was shown to be an improvement over the previous “three stimulus” P300-based concealed information tests (CITs). Not only was it highly accurate with autobiographical information but was also resistant to the use of countermeasures (CMs). The current study applied the CTP to the detection of incidentally acquired information in a mock crime scenario. In previous “three stimulus” mock crime studies utilizing P300-based CITs, participants memorized a guilty knowledge item(s). Special care was taken in the current study to ensure that participants' knowledge of the guilty item in the mock crime was obtained only during the commission of the act in order to bolster ecological validity. Overall, 92% of all participants in guilty, innocent, and countermeasure conditions were correctly classified. CM use was again indexed by reaction times (RTs).