This research is the start of a systematic validation of radiographic comparison methods for making positive identifications of decomposed bodies based on several anatomical features and skeletal characteristics.
Three standard body regions were selected for this study of the anonymous radiographs of 858 adults and 148 juveniles from the North Carolina Office of the Chief Medical Examiner: lateral cranial radiographs, chest radiographs, and radiographs of the proximal femur. Overall, the study established the minimum number of concordant areas needed to confirm positive identifications in three standard radiographic views. All three methods used to assess cranial vault outlines in lateral cranial radiographs determined that the shape of the vault is not sufficiently unique to make an individual identification. Two or more points of concordance are required in lateral cranial radiographs for a 97-percent probability of a positive identification. The results of the chest radiographic analysis showed that the anatomical elements with the most predictive values were the cervical vertebrae. If more than one concordant feature exists, there is a 99-percent probability of a correct identification If no cervical concordant features are presents, four or more concordant features of the other vertebrae are required for a 98-percent probability of having a correct identification. This probability drops to 79 percent when less than four concordant lumbar features are present. For the femur, if there is one or more femoral head concordant features, the probability of a correct identification is 93 percent and 97 percent with concordant neck traits. For the greater trochanter, the probability is 76 percent with one or more concordant features and 93 percent if there are two or more concordant features for the lesser trichinae. The system used should serve as a model for future research on positive identification using radiographs. 17 figures, 6 tables, and 45 references