TY - JOUR
T1 - Validation of forensic facial comparison by morphological analysis in photographic and CCTV samples
AU - Bacci, Nicholas
AU - Houlton, Tobias M.R.
AU - Briers, Nanette
AU - Steyn, Maryna
N1 - Funding Information:
The current study was conducted with support from the South African National Research Foundation (NRF) and the J.J.J. Smieszeck Fellowship from the School of Anatomical Sciences, University of the Witwatersrand (DAAD-NRF and J.J.J. Smieszeck Fellowship funds awarded to N. Bacci (Grant No.: 11858) and NRF funds awarded to N. Briers as part of the Improving Methodologies and Practices in Craniofacial Identification (Grant No.: CSUR160425163022; UID: 106031). Any opinions, findings, and conclusions or recommendations expressed in this study are those of the authors and therefore the NRF and University of the Witwatersrand, Johannesburg, do not accept any liability in regard thereto.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
PY - 2021/9
Y1 - 2021/9
N2 - Between the ever-increasing availability of surveillance evidence and expert-based forensic facial comparison being considered admissible in court, confirming its validity is paramount. Facial comparison is most commonly conducted using morphological analysis (MA), a largely untested feature-based approach. This study aimed at validating the current recommended practice of MA in both standardised and suboptimal surveillance samples. Face pools of 175 South African males were compiled with a series of facial photographs, using images from the Wits Face Database. The first 75 face pools consisted of wildtype (unstandardised) high-quality target photographs, while the remaining 100 face pools consisted of suboptimal closed-circuit television (CCTV) target images. Target images were compared to high-quality standardised photographs. Face pools were analysed using the Facial Identification Scientific Working Group’s guidelines and feature list. Confusion matrices were used to determine the performance of MA in each cohort. MA was found highly accurate (chance-corrected accuracy (CCA): 99.1%) and reliable (κ = 0.921) in the photographic sample and less accurate (CCA: 82.6%) and reliable (κ = 0.743), in the CCTV sample. Higher false-positive and false-negative rates were noted for the CCTV sample, with the majority of errors resulting in false-negative outcomes. The decreased performance in the CCTV sample was attributed to various factors including image quality, angle of recording and lighting. Other studies testing facial comparison identified lower accuracies and reliability across various conditions. Better performance was found here and in other studies that included some form of facial feature list, reinforcing the importance of using a systematic facial feature list.
AB - Between the ever-increasing availability of surveillance evidence and expert-based forensic facial comparison being considered admissible in court, confirming its validity is paramount. Facial comparison is most commonly conducted using morphological analysis (MA), a largely untested feature-based approach. This study aimed at validating the current recommended practice of MA in both standardised and suboptimal surveillance samples. Face pools of 175 South African males were compiled with a series of facial photographs, using images from the Wits Face Database. The first 75 face pools consisted of wildtype (unstandardised) high-quality target photographs, while the remaining 100 face pools consisted of suboptimal closed-circuit television (CCTV) target images. Target images were compared to high-quality standardised photographs. Face pools were analysed using the Facial Identification Scientific Working Group’s guidelines and feature list. Confusion matrices were used to determine the performance of MA in each cohort. MA was found highly accurate (chance-corrected accuracy (CCA): 99.1%) and reliable (κ = 0.921) in the photographic sample and less accurate (CCA: 82.6%) and reliable (κ = 0.743), in the CCTV sample. Higher false-positive and false-negative rates were noted for the CCTV sample, with the majority of errors resulting in false-negative outcomes. The decreased performance in the CCTV sample was attributed to various factors including image quality, angle of recording and lighting. Other studies testing facial comparison identified lower accuracies and reliability across various conditions. Better performance was found here and in other studies that included some form of facial feature list, reinforcing the importance of using a systematic facial feature list.
KW - CCTV
KW - Face mapping
KW - Facial identification
KW - FISWG
KW - Forensic facial comparison
KW - Morphological analysis
UR - http://www.scopus.com/inward/record.url?scp=85100950067&partnerID=8YFLogxK
U2 - 10.1007/s00414-021-02512-3
DO - 10.1007/s00414-021-02512-3
M3 - Article
C2 - 33594456
AN - SCOPUS:85100950067
SN - 0937-9827
VL - 135
SP - 1965
EP - 1981
JO - International Journal of Legal Medicine
JF - International Journal of Legal Medicine
ER -