Criminal investigation is a complex undertaking requiring the ongoing development of specialist techniques. Eye tracking methods are used in psychological research to measure attentional focus and informational intake to visual stimuli. Previous research posits prior fixation on a scene aids its later recognition, which is reflected in gaze behaviour through increased fixation on familiar parts of the image and repeated patterns of fixations upon re-viewing an image. This presents applications in suspect identification; investigators may be able to infer whether a suspect has memory of a crime from their eye movement patterns to the crime scene. The present study tests a new data-driven methodology developed by Onwuegbusi et al. (2022) comparing differences in Experts’ and Novices’ gaze behaviour while viewing a crime scene.
Four groups of participants (n = 83) watched videos depicting a violent or non-violent crime while their eye movements were tracked. The Experts watched either a video depicting a stabbing or a petty theft, followed by a neutral video of the empty crime scene after two days. The Novices first watched the neutral video, then followed the same process as the Experts.
Prior exposure to the crime increased Experts’ subsequent attentional focus on areas of the environment the crime occurred in. Experts fixated more on the location of the crime than Novices, suggesting priming effects. Some participants averted their gaze from the stabbing location despite being primed. This study also investigates whether gaze aversion is due to the violent nature of the crime and participants’ related anxiety. Participants with higher Gaze Anxiety Rating Scale scores demonstrated increased gaze aversion from the crime location after viewing violent, but not nonviolent, footage and fixated more on less emotionally salient distractions. This aligns with existing theories associating high trait anxiety with gaze aversion from harm-related stimuli to alleviate distress.
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