Advances in the Use of Craniofacial Superimposition for Human Identification

The Critical Photographic Variables Contributing to Skull-Face Superimposition Methods to Assist Forensic Identification of Skeletons: A Review

“…This photographic dependence fundamentally sets the method to be a photographic technique, however, input from photographers has been the exception rather than the rule, see, e.g., [14]. Generally, forensic odontologists [4,[15][16][17] and anthropologists [7,13,[18][19][20][21] have driven method progress, resulting in some important, though basic, photographic and optical parameters being overlooked. The aim of this paper is to bring these photographic considerations to the fore.…”

“…Historically, two video cameras have been employed, one recording a hardcopy of the facial photograph and the other recording the skull [4,5,19,[21][22][23][24]. A video mixer is used to overlay or superimpose the two images such that they can be directly compared [4,25].…”

“…A video mixer is used to overlay or superimpose the two images such that they can be directly compared [4,25]. Often the skull is orientated by eye (to match the pose of the head in the AM image), on a simple cork ring (or beanbag) that supports the skull [19,21,22]. In some more advanced superimposition systems, a computer control unit is used to adjust the rotation/pan/tilt actions of the skull via robotic motors (Figure 2) [1,4,26].…”

“…The ongoing issues with reliability have driven increasingly common recommendations in the field that the method only be used as an exclusionary tool [1,10,19,22,27], not for positive identifications. While this exclusionary use is now generally accepted [1,10,19,22,27], it should be noted that this approach provides no safety net for false negatives, which continue to be problematic.…”

“…The ongoing issues with reliability have driven increasingly common recommendations in the field that the method only be used as an exclusionary tool [1,10,19,22,27], not for positive identifications. While this exclusionary use is now generally accepted [1,10,19,22,27], it should be noted that this approach provides no safety net for false negatives, which continue to be problematic. That is, unreliable methods, even if reserved for exclusions are still likely to produce erroneous results-a factor that has received far less attention in craniofacial superimposition literature [8,39,77].…”