The feats of technology never cease to amaze us. From the invention of the telephone in the 1800s to the invention of today’s artificially intelligent voice-detecting devices that can assist individuals in their daily tasks, technology is making our lives easier in all spheres. Eye-tracking technology is one such thrilling enterprise that is currently proven to be useful and convenient to humans in all domains!
Eye-tracking technology refers to the process of tracing the movement of one’s eyes when they look at a specific object or an entire collection of objects, known as the ‘point of gaze.’ A head-mounted, wearable device was initially used to measure the gaze points; however, a much-sophisticated wearable set of spectacles have been introduced that achieve the purpose just as easily.
Eye-tracking devices, such as the wearable Tobii pro glasses, work by observing the behavior of the eyes as they move around and record the patterns of behavior which constitute pupil dilation, focus loss, eye fixations, and so forth. The two significant points of focus while measuring the eye movements are “points of interest,” often called fixations and saccades, which is the movement of an individual’s eyes between the points of fixation.
This technology, to a greater extent, is used in market trend research. However, one of the fields where eye-tracking has been used, to an unquestionable degree successfully, is Crime Scene Investigation and Prevention. In recent times, several departments within law enforcement have started to rely on the accuracy of eye-tracking technology to investigate criminal activities and apprehend the guilty parties based on their eye behavior.
Crime Scene Investigation
During investigations, the uses of eye-tracking methods help investigators detect deceit. Within eye-tracking, the measurement of eye gaze movements can be used to analyze the behavior of individuals. Crime scene analysts are at the morrow of criminal investigations; the decisions made by them, the forensic evidence found and logged by them become crucial in bringing any investigation to its accurate resolution. Any misstep or failure to recognize items of significance can limit the progress of the investigation.
Therefore, it becomes critical for these analysts to properly acknowledge and evaluate evidence for the benefit of the case. This is why crime scene analysts often wear eye-tracking glasses while observing crime scenes as this helps pinpoint areas of interest throughout the scene, such as the pattern of blood spatter or signs of a struggle inside a bedroom. This also enables them to regard or disregard any item that may or may not be of relevance. Eye-tracking also helps reconstruct scenes just as they are since it does not depend on memory or individual reports, thereby limiting room for human error.
Interrogating suspects is somewhat tricky when the person being questioned happens to be a professional or a practiced liar. However, where words paint a seemingly honest picture, facial movements, micro-expressions, movement of one’s eyes often give them away. These are not always easy to assess or measure. One of the essential tools used by police detectives during the interrogation of suspects is observation.
Where polygraph tests (lie-detection tests) fail, eye-tracking technology helps! While both these tools are considered as indispensable during investigations, the precision of eye-tracking demonstrate a far greater acquisition of results. By tracking the eye movements, the gaze and the eye fixations, and the areas of interest, a suspect’s responses can be gauged and categorized as lies or the truth. How long the sight lingers on an image or object they recognize or not is very telling of the facts individuals hide or share with the authorities who question them.
During interrogation, the suspects are shown documents, pictures, and objects, some of which are relevant to the crime while others are crime-irrelevant (often known as “foil” objects). While the suspect goes through these objects, their eye-fixation is measured. When the eyes of the suspect move from unfamiliar objects to familiar ones, significantly fewer eye-fixations are produced. It happens due to the suspect’s recollection of those items if they recognize them.
Eyewitness accounts are attestations provided by individuals of an event that they have witnessed; these events could be range from recounting a robbery they saw or to provide alibis for people who may be under suspicion by a court of law. Eyewitness testimonies are generally considered unreliable as they are often subject to individual memory biases, influence of stress or anxiety, or simply wrong recollection of events.
This is why eye-tracking is considered to be a useful tool to avoid the faults in recall when interacting with individuals who are witnesses to certain crimes or criminals. This is done through the measurement of visual attention that is then distinguished based on the task being performed by an individual, such as identifying suspects in a lineup or looking at pictures/objects and so forth.
Eye-tracking is especially useful during sequential suspect lineups, where it provides real-time information about the decision processes the individual goes through as gaze is continually monitored throughout the entire process. The better the individual recognizes a “suspect,” the easier it becomes to identify them based on the pattern of fixations as well as areas of interest. These lineups generally consist of actual suspects as well as foil or crime-irrelevant individuals, making it even easier for witnesses to concentrate only on those they recognize from the crime scene with the convenience of eye-tracking technology.
Using advanced technology such as eye-tracking devices during criminal investigations makes it significantly easier and time-efficient for investigators to conduct investigations and apprehend the guilty party. Since eye-tracking does not depend on fallible human memory and also reduces the possibility of human error, it increases the prospect of quicker case resolution. Eye-tracking analysis can also lead to discoveries that might have been missed during the initial sweep on a crime scene.