This field study tested the validity of the Integrated Zone Comparison Technique (IZCT) designed for specific issue testing and the ASIT PolySuite Algorithm for data analysis in a private commercial environment between April and December 2009, at the G4S polygraph unit in Costa Rica. During this time period 27 cases were chosen to be tested with the IZCT. Out of these 27 cases, 21 were solved by confession. The 27 cases had a total of 113 suspects. Out of the 113 tests, 84 were confirmed results. Of these, there were 44 confirmed deceptive examinees and 40 confirmed innocent examinees. Data analysis was performed with the Academy for Scientific Investigative Training’s ASIT PolySuite©, which is an examiner-controlled computerized algorithm, using the Horizontal Scoring System (HSS), as well as an experienced examiners analysis using a 3-Point Scale, IZCT, using ASIT PolySuite, had an overall accuracy of 92.9% with Inconclusives, and 98.73% accuracy excluding them. Manual 3-point scoring had an overall accuracy of 91.7% with Inconclusives, and 98.71% excluding them.