The Eyewitness Expert
~ Dr. Paul Michel is an eyewitness expert specializing in eyewitness identification and eyewitness testimony regarding false identification and threat assessment. ~
Experience as both a Doctor of Optometry and a specialist police investigator qualifies Dr. Michel to give expert testimony and opinions on eyewitness identification - an eyewitness expert.
Eyewitness identification is possible only through the sense of vision. Eyewitness testimony can be a very powerful tool in determining a person's guilt or innocence. It can also be devastating when false eyewitness identification is made. False eyewitness identification can occur because the eyewitness is either honestly confused or is deliberately dishonest. Honest confusion on the part of the eyewitness can occur because the vision is imperfect and the eyes are fallible as sensory organs. I have encountered eyewitnesses that report seeing the impossible. Yet, they are convinced that they have seen things beyond their capability.
If the proper elements for vision are met, eyesight can be extremely keen for detail and color. Under the right conditions vision eyewitness identification can be very valid. There are also conditions that a witness's ability to make valid observations can be substantiated. Conversely, if these conditions are not met, vision can be very poor and unreliable. An eyewitness observation should be evaluated by an expert and its validity assessed. Environmental conditions that limit vision include: low lighting, movement, time constraints, distance, eye disease and other factors. These factors affect the conditions of visibility and determine what an eyewitness may or may not have reliably witnessed.
How Eyewitness False Identification Can Occur
The study of human vision can be incorporated in criminal, traffic collision or use of force/self defense investigations. Police investigators generally don't understand the significance of the visual environment under which witnesses made their observations. This is to be expected as they are police investigators and not experts in eyewitness identification.
Typically, police investigators arrive at darkened crime scenes and turn on lights or use flash photography to document conditions. The emphasis of their investigating is physical conditions of the crime scene and not of the conditions of visibility during the crime. Unfortunately, this can lead to a false notion of what the conditions of lighting and visibility were for the eyewitness. Once the lights are on, movement has ceased, and time constraints are no longer an issue, a witness' reported observations may erroneously be considered as valid. It would be rare for a police investigation to document the lighting at the darkened crime scene. The precise lighting level and pattern of lighting may be a major factor in determining validity of eyewitness identification; therefore, it should be documented.
The eyes passively collect light and focus it on its back surface called the retina. The retina has the receptors that convert light into nervous impulses. These nervous impulses are transmitted to the brain along the optic nerve. The brain then integrates these images with memory, cognition and expectation to form a perception. Perceptions are momentary and personal events. Once the perception occurs, the witness relies on memory. Memory other cognitive facets of eyewitness identification are soft sciences. The conditions of visibility and ocular physiology are hard sciences are subject to less interpretation.
The light that enters the center of the eye stimulates a different type of receptor than that which enters the periphery. The receptors in the center of the retina are called cones; those in the periphery are called rods. When the light is not sufficiently intense, the cone receptors that provide fine detail and color, are not stimulated. When the conditions of visibility are limited, the eyes transmit incomplete information to the brain. The brain incorporates this incomplete information with past experiences, memory and cognition to experience a logical outcome. This outcome is the witness' perception. The perception can be flawed. The results may be a perception based more on what they brain has filled in, than what was actually seen by the eyes. A thorough understanding of vision is necessary. All sensory organs have limitations and the eyes are no exception. These limitations can cause erroneous identification on the part of the eyewitness. An expert opinion can delineate reliable from unreliable eyewitness testimony.
Regrettably, false eyewitness identification does occur. My investigations have helped to establish innocence at initial trials and upon appeal. Conversely, other investigations have established witnesses' ability to have actually seen what they reported. Scientifically derived knowledge establishes what parameter are consistent with valid eyewitness identification. There is a sufficient scientific knowledge body to determine the parameters of vision sufficiently good to make facial identification of a suspect.
The parameters of vision also have been applied to determine whether a defendant could have discerned enough detail to differentiate a lethal from a non lethal item while it was brandished. While Dr. Michel served with the Los Angeles Police department's Officer Involved Shootings Investigation's Unit, there were incidences where an officer shot a suspect who was later determined to be unarmed. The investigation conducted initially did not document nor consider the effects of low lighting, quick furtive gestures, and eye movements necessary to track the object in suspect's hands, time constraints and other factors. When all of the factors were considered, the court determined that the shooting was justified. My subsequent investigations into citizen use of force have also produced useful information that had previously gone undocumented.
An eyewitness's testimony can be very persuasive. The witness can have an emotional connection to the jury that physical evidence can't possess. But human vision is fallible. An eyewitness testimony should be evaluated to ascertain if the witness could have seen what they claim to have seen.