The postmortem cooling rate of the brain, liver, and rectum were measured in 117 forensic cases (Part I, see NCJ-187613). The method can be used in the field as a computer program, reference graph, or reference chart-ruler. The program is simple and can easily be run by any user. There are six reference graphs that represent the average brain, liver, and rectal cooling curves for naked and covered body groups. The ruler is designed for the rectal cooling curves for covered naked bodies. This method requires one temperature measurement of the chosen body site and the environment. The postmortem interval is estimated as a probable value plus or minus a possible range of time estimates with a built-in confidence limit. To enable practicing pathologists or forensic examiners to use the TEF developed in this study for more accurate estimation of the time since death, a specially written simple computer program was prepared. The program operates in any Windows operating system. Following the instructions given by the program, the investigator is asked to input the temperature of a body site and the temperature of the environment and to indicate which body site is used (rectum, brain, or liver). Other data required for the prediction of the postmortem interval are built into the program itself. The authors believe that the method they have developed provides significant improvements in the accuracy and reliability of postmortem time estimates compared with other methods; however, it is recommended primarily as an investigative tool rather than as a source of evidence. 2 tables, 2 figures, and 18 references