There is much that can be said eyewitness testimonies and their place in the use of solving crimes, and the psychology behind them. While they are often used to solve crimes, the truth is that the human memory is a very malleable, unreliable thing and that many psychological factors should be considered when considering the reliability of eyewitness testimonies. To examine this, first I will look at a case study where an unreliable eyewitness testimony led to the wrongful conviction of an innocent man.
In 1984, on one night, a man broke into a woman’s house and proceeded to sexually assault her. Her name was Jennifer Thompson, at the time, she was a 22 year old student. After this crime, police began an investigation. She then proceeded police to create a sketch of what the man looked like, as she had taken it upon herself to remember as many of his features as possible during the assault. Just hours after the assault, after she had been swabbed for any DNA samples left by the perpetrator, she helped police create this sketch. She picked out multiple features of him that she had remembered. For example, his eyebrows, his nose and the fact that he had a very thin moustache. Following a search, just a week later, the police rounded up multiple men who bared a resemblance to the man provided in the police sketch. After this, she was shown multiple photos of the men. Of all the men, she chose one man. While at first she selected him with a bit of apprehension, eventually her confidence grew more and more and with absolute certainty she confirmed that this was the man that had raped her that night. This man was known as Ronald Cotton, a 22 year old black male. He had previous encounters with law enforcement, in particular, he had previously served an 18 month sentence for attempted sexual assault, and following a search of his house, they determined he had been the perpetrator, tying him to the crime scene with a footprint and a flashlight that resembled the one used by the suspect, along with Thompson’s eyewitness testimony. In January 1985, Cotton was convicted of one count of rape and also with one count of burglary. Thompson finally felt that justice had been served, and that the right man was behind bars. During the trial and following incarceration, Cotton vehemently denied his involvement in the case and was adamant that he was an innocent man, wrongly convicted.
Unfortunately, this was not the case. During his time in prison, another inmate, Bobby Poole, had been bragging to prisoners that he was also guilty of committing the rape of Thompson. Not only this, but an hour after the rape of Thompson, in the same neighbourhood, another woman was raped in the same style as Thompson. Police were certain that the same man had committed both crimes. Managing to use his lawyer to call Poole to the stand, Cotton managed to bring an appeal before the court, once again defending his innocence. However, during the trial, Poole denied all these accusations when he was taken to the stand. And more importantly, the eye witness and key part of the trial. She looked at both Poole and Cotton. She then denied ever seeing Poole and reaffirming her view that Thompson was guilty. Then the victim of the second rape looked at both Poole and Thompson. Not only had the lost the appeal, he had been given a second life sentence for the second rape he had now been deemed to have committed.
It took 11 years for Cotton to finally reach a positive breakthrough. With the advent of new DNA technology, he was finally able to clear his name. The samples from Thompson were tested and showed no match to Cotton. He had finally been proven innocent. Not only this, but the DNA had finally confirmed that Poole was, indeed, guilty of these crimes.
But where had it all went wrong for Thompson? Police had described her as the perfect witness. However, it became very clear that Poole and Cotton only looked similar on a very superficial level. How could someone who have spent so long not only focusing on her attacker’s features but also attempt to commit it to memory make so many mistakes? There are multiple psychological factors at play here. It is important to examine every aspect of when this crime took place to understand the failings of the eyewitness testimony.
According to research, over 4250 Americans every year are thought to be wrongfully convicted of a crime due to a false identification by either the victim of the crime or a witness. The National Justice Institute of America even conducted a study and found that 80% of overturned wrongful convictions are because of eyewitness testimony.
According to a study by (Loftus 1974), eyewitnesses are almost always believed. In this study, Mock Jurors were presented with a court case where a suspect was believed to have committed a robbery and the murder of 2 people. When no eyewitness testimony was provided and only circumstantial evidence could be given, only 18% of the jury convicted the suspect. However, when provided with an eyewitness testimony and the evidence, this number shot up to 72%. Even when the jury is told that the eyewitness has very poor eyesight, this number only decreased by 4% down to 68%.
Studies not even show that eyewitness testimonies are believed, but they can even be believed more than things such as physical evidence (McAllister, Bregman 1986), alibis (McAllister, Bregman 1989).
Despite all this, testimonies are undeniably very unreliable due to the nature of human memory. As the crime becomes more violent and thus more stressful to the witnesses, they can become even more unreliable, and distort memory. Memory can be distorted in multiple ways. One form of this is misinformation. A person’s memory can be proven to be manipulated after being exposed to misleading information regarding that information. For example, a person who is shown a photo of what may be the perpetrator of a crime will tend to believe that person is responsible. This is because this photo will distract the original memory and distort it. This is not intentionally deceitful by the police; however, it can distort the memory all the same and muddy the truth. It is also possible to change what a person remembers or views a memory by the words used when phrasing questions. This is known as suggestion. For example, a group of students were shown the same footage of a car crashing. Students who were asked “how fast the cars were going when the cars smashed into each other” on average gave a speed of 20% faster than the students who were asked “how fast the cars were going when the cars hit each other?” This is due to the subtle wording used can trigger how the memory is viewed in the student’s head. The same effect was achieved during the study when asked a question regarding a car crash. The questions were the same, however, the students were then asked if they saw broken glass at the scene of the accident. Those who were asked the question with the word “smashed” over “hit” were also twice as more likely to report seeing the broken glass, when, there was no glass present. (Loftus 1974)
There are other ways memory can be manipulated or end up being distorted. For example, if an eyewitness is told that their selection in a line-up of possible suspects was correct, this would lead to them believing more that their selection was right than if the police did not inform them, even when this is not the case. This can also occur when negative feedback is given, and a person will start to doubt their own memories and second guess themselves. There is also an effect known as the weapon focus effect. When a weapon is present during a crime, this greatly reduces the accuracy of attempts to either identify the suspect or to even recall details of the crime. This is because the perceived threat of the weapon is greater than focusing on other details. It can also be attributed to increasing levels of stress and anxiety in the brain which can also interrupt the encoding of memory. This is because we generally expect weapons around us and thus when they appear, we must focus and ascertain their threat level to us. Our eyes will track the weapon, thus drawing attention away from the holder of the weapon.
There have also been numerous studies done that support the theory of cross-race identification. This is the theory that we have more trouble identifying features of people in a race different to our own. It has been proven by studies that cross-race identification will be consistently weaker than own-race identification. This is due to the fact that we are more able to discern features in faces similar to our own and our brain has a simpler time processing them, due to a closer genetic similarity. While the effect has been proven in a study of African and Caucasian faces by (Meissner, Brigham 2001), it also applies to other races, for example, Caucasian and Asian, etc.
Multiple studies have also shown that the illumination factor plays a major role in our recall of a memory. On top of that, longer exposure to something will also increase the accuracy of identification. According to a study by (Loftus et al, 1987), witnesses tend to overestimate the length they have viewed something by up to 60%. A study done by Yarmey (1986) investigated recall and identification during 4 different times of the day. These were during daylight, the beginning of twilight, the end of twilight, and night time itself. It was found that the presence of light has a major effect on recall and that the more there is a light source present, the more accurate the memory will be.
It is also found that if a suspect adds features that were not present during the crime, for example, glasses or a hat, a witness will have a much harder time positively identifying them. This also applies the opposite way, for example, if a suspect has a moustache during a crime and promptly shaves it, this will make it harder for a positive identification to be made. (Cutler et al., 1985)
As we saw in the Cotton case, confidence too can play a major role in memory recall. The more Thompson’s confidence grew that Cotton was her rapist, the more she truly believed it was him, even when this proved to not be the case. It is also important to note that the individual characteristics can have a big influence on the quality of the memory that is being recalled. For example, according to (O’Rourke et al., 1989) and (Valentine et al., 2003), young adults tend to make the most reliable eyewitnesses, superior to both young children and older adults. It has been shown that elderly witnesses are more likely to possess worse memory than their younger counterparts in a study by (Aizpurua et al., 2009) Substance use, such as the consumption of drugs and alcohol, can have a major negative impact. Not only can such substances negatively impact vision, they also increase the likelihood of choosing in a lineup of potential suspects. These of course, when combined, can lead to people being wrongfully identified.
When we look at the Cotton case, we can see that there were a lot of these factors at play. The rape occurred in low illumination, which affected Thompson’s vision. Poole had also held a knife to her throat when committing the act, causing the weapon focus effect to also take place. On top of this, the act itself of being sexually assaulted can have a major negative impact on one’s ability to encode information probably due to the high stress levels caused by such a horrific ideal. There is also the presence of a need for justice in Thompson’s mind, which caused her to subconsciously suggest to herself that Cotton must have been the man to have committed the crime. There is also of course, the cross-race effect. Cotton and Poole are both men of African descent while Thompson is a Caucasian woman. While Poole and Cotton are only similar on a superficial level, Thompson could not discern this even after seeing both men. There is also the possibility that, unintentionally, the police may have guided her towards selecting Cotton as the man who committed the crimes when conducting the lineup and the photograph viewing.
Overall, I think that due to the abundance of statistics and psychological research present, it is quite clear that eyewitness testimonies are quite fallible and over-relied on by the courts. On top of this, memory is not something so simple that it can be broken down and applied the same way in each case. There are many influential factors that play a part in the recall of an event, from the characteristics of the witness, to the characteristics of the perpetrator and the details of the event itself, such as the level of light or the presence of a weapon. In my opinion, there should be great care taken in the use of witnesses both by the judiciary and the law enforcement. A great deal of power is placed into the hands of these testimonies, yet they so often result in innocent people being convicted. I believe that every step in the use of eyewitness testimonies should be rigorously analysed and that there should be a guideline created. This guideline would teach law enforcement, such as the sketchers and the detectives, how to avoid interfering with the recall process of the witness, either by priming, suggesting. Given how easy it is to manipulate a person’s memory, a great deal of care is needed in how this process is conducted, in order to ensure that more innocent people like Ronald Cotton lose valuable years of their life for an action they didn’t commit.
- Fawcett, M, J., Pearce, A, K., Greve, A. (2016) ‘Looking Down the Barrel of a Gun: What Do We Know About the Weapon Focus Effect?’ Journal of Applied Research in Memory and Cognition, Volume 5(3), 257-263, available: https://doi.org/10.1016/j.jarmac.2016.07.005
- Franklin, N. (n.d.) A Brief Guide to Factors that Commonly Influence Identification and Memory For Criminal Events, Dept. Of Psychology, Stony Brook University. Available: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.471.475&rep=rep1&type=pdf [accessed 29 Nov 19]
- National Research Council. (2014) Identifying the Culprit: Assessing Eyewitness Identification. Washington, DC: The National Academies Press
- Lacy, J. W., Stark, C. (2013) The Neuroscience of Memory: Implications for the Courtroom. Nature Reviews. Neuroscience, 14(9) 649-658, available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183265/