Police Witness Identification Images: A Geometric Morphometric Analysis*

Abstract

Research into witness identification images typically occurs within the laboratory and involves subjective likeness and recognizability judgments. This study analyzed whether actual witness identification images systematically alter the facial shapes of the suspects described. The shape analysis tool, geometric morphometrics, was applied to 46 homologous facial landmarks displayed on 50 witness identification images and their corresponding arrest photographs, using principal component analysis and multivariate regressions. The results indicate that compared with arrest photographs, witness identification images systematically depict suspects with lowered and medially located eyebrows (p = <0.000001). This was found to occur independently of the Police Artist, and did not occur with composites produced under laboratory conditions. There are several possible explanations for this finding, including any, or all, of the following: The suspect was frowning at the time of the incident, the witness had negative feelings toward the suspect, this is an effect of unfamiliar face processing, the suspect displayed fear at the time of their arrest photograph.

A geometric morphometric evaluation of the Belanglo ‘Angel’ facial approximation

“…The photographs are of young women of recorded or apparent European population ancestry with a recorded or apparent age of [18][19][20][21][22][23][24][25] years, and only closed-mouth smiles were selected from the images displaying this facial expression. The database images were sourced as follows: To avoid confusion, hereinafter all references to the PAL, Utrecht and/or Pasco Sheriff Arrest Databases will be capitalised, while the database of images composed of the three Database and internet photographs (n=64) will be lower case.…”

“…In August 2010, the skeletal remains of a young woman (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) years, European population affinity) were found in Australia"s Belanglo State Forest. A year later, the New South Wales Police requested a facial approximation and the results were released to the national media in December 2011 (Figure 1a).…”

“…If anthropometric measures reference photographs, each individual needs to be photographed bearing the same head orientation and facial expression, and the camera angle and lens-subject distance needs to be standardised so as to reduce, but not entirely remove, the effect of perspective distortion [see, for example , 24]. Images taken outside of the laboratory, including arrest photographs, tend not comply with these requirements [25]. Instead, most photographs typically differ in head pose, facial expression, camera make and camera angle as well as variation in lenssubject distance, and this holds true for the photographs of Ms Pearce-Stevenson published in the Australian media.…”

“…Because of its capacity to process complex patterns of shape variance, previous research has found that geometric morphometrics can enable statistically meaningful comparisons between (i) highly disparate image types depicting the face of the same individual [25,26], (ii) widely divergent palaeoart facial reconstructions of the same skull [27], and (iii) between images of different individuals displaying a range of habitual head pose variations [28]. It is because of this ability to identify shape variance due to head pose that geometric morphometrics has been applied for this evaluation of the facial approximation of Ms Pearce-Stevenson, though photographic distortion remains a confounding variable.…”

Geometric morphometrics and face shape characteristics associated with chronic disease in the elderly

“…In the same way that the face is capable of expressing innumerable feelings and sensations, it can reveal population differences, aid in identification in criminal cases and in some contexts detect the state of health or presence of syndromes (DEMAYO et al, 2009a;HAYES;TULLBERG, 2012;SCOTT et al, 2013;PRASAD et al, 2015). Facial markers associated with computer recognition have generated interest from different disciplines and research areas (MAYER et al, 2017).…”