Limitations of Eye Witness Testimony

Written By: David M. Buckley*
Mar 18, 2024

In our legal system, judges, attorneys, juries and witnesses diligently strive to uphold ethical standards, best practices, and to stay informed of court and legislative decisions that impact the judicial process. Despite these efforts, the inherent nature of dealing with human beings introduces the inevitability of human error.

Analogous to the medical field, where preventable deaths due to medical malpractice rank as the third leading cause of death in the United States (Martin Makary 2016), legal professionals face their own set of challenges. In the pursuit of justice mistakes are made, revealing vulnerabilities within the legal system.

Wrongful convictions, a grave consequence of these errors, can stem from various factors. Inaccurate eyewitness testimony, tainted by the fallibility of human memory, stands out as a prominent contributor. Poorly substantiated scientific evidence, faulty expert witness testimony, and errors in police and prosecutorial conduct further compound the risks of wrongful convictions. Inadequate defense representation also plays a significant role, leaving defendants vulnerable to miscarriages of justice. False confessions, coerced or influenced by various factors, add another layer of complexity to the legal landscape. The weight of community pressure can further skew the pursuit of truth and justice. Efforts to minimize errors in the legal system must extend beyond acknowledging the inevitability of human error. Embracing advancements in forensic science, implementing rigorous standards for expert testimony, and enhancing training to mitigate police and prosecutorial misconduct are crucial steps. Strengthening defense representation, fostering awareness about the potential for false confessions, and shielding legal proceedings from undue community influence contribute to a more robust and just legal framework.

Jim Petro, a former Attorney General of Ohio, sheds light on the alarming prevalence of wrongful convictions. His work, including co-authoring "False Justice," reveals that in 75% of DNA-based exoneration cases, eyewitness testimony served as the primary evidence. This statistic underscores the critical role of human perception and memory in shaping legal outcomes. Errors stemming from faulty eyewitness testimony, as Petro emphasizes, emerge as the foremost reason innocent individuals find themselves wrongly convicted. This revelation calls for a meticulous reevaluation of the reliance on such testimony in legal proceedings.

Eyewitness testimony is often faulty due to the fragility of human memory. Perception varies among individuals, memories can be incomplete or contaminated, and recall attempts may alter the original memory. I’m not sure what the dress and audio are in reference to…let me suggest an option…. see text below {Many remember the social media phenomenon of the ‘dress’; is it black and blue or is it gold and white. Some perceived the dress as gold and white while others perceived it as black and blue (the dress was black and blue). In yet another social media event, an audio recording was played, and listeners were asked to identify what they heard. The choices were ‘Yanny’ or ‘Laural’. Of the respondents, 47% perceived the sound as ‘Yanny’ and 53% perceived the sound as ‘Laural’. Both instances illustrate how perception varies among individuals.} Consider the well-known law school experiment in which an unknown male rushes into the lecture hall, screams a threatening statement, fires a gun into the ceiling and runs out of the room. The students are then asked to write down a description of what the intruder looked like, what he said, and what he did. As you can imagine the descriptions vary widely from 5 feet four inches to six feet 3 inches; an American accent to a Spanish accent; wearing a red jacket to wearing a grey hoodie, etc.

Even though most eyewitnesses do not intentionally provide misidentification they are often mistaken due to a variety of reasons. One such condition is when an eyewitness makes a cross-race identification. (Meissner & Brigham, 2007) Law enforcement should take particular care and be especially vigilant about using proper identification procedures in cross-race identification. In-court identifications are known to be unreliable and are subject to the power of suggestion. Placing a witness on the stand in court and knowing that the defendant is being charged for the crime by the state, asking them if the person who committed the crime is in the courtroom has little value. An eyewitness’ memory should instead be properly tested long before the trial. Even though eyewitness identification can be unreliable it can be very persuasive to a jury. According to the Innocence Project, incorrect in-court identifications appear in at least one-third of DNA exonerations.

How an eyewitness is questioned can influence the accuracy of their memory and result in misinformation as illustrated in an early study (Loftus, Miller, Burns, 1978). After viewing a slideshow of a red car hitting a pedestrian, the subjects were asked, “How fast was the car traveling when it passed the yield sign?” The slide depicted a ‘stop sign’ not a ‘yield sign’. When questioned later, the subjects were shown two slides, one depicting a ‘yield sign’, the other depicting a ‘stop sign’ and asked to choose which was accurate, those who were asked the questions about the yield sign were more likely to pick the slide with the yield sign. The leading question containing misinformation led to inaccurate memory. The way eyewitnesses are questioned can significantly impact the accuracy of their memory, with leading questions or subtle wording differences influencing recall, as illustrated by studies on misinformation and memory distortion. This phenomenon emphasizes the need for carefully handling eyewitness identification in legal proceedings. Even slight differences in the wording of a question may alter memory (Loftus, 1975). Subjects were more likely to say yes when asked “Did you see the broken headlight?” vs “Did you see a broken headlight?”

Indeed, human perception is intricate and susceptible to selective attention. The Invisible Gorilla experiment, conducted by Harvard University, vividly illustrates how our focus on a specific task can cause us to miss significant details, like a gorilla in the video. Our minds filter information, and what we notice is shaped by our attention and past experiences, highlighting the dynamic nature of memory formation and perception. In the study at Harvard University a video was shown to students where two teams of individuals were passing a ball back and forth, one wearing white shirts and the other wearing black shirts. The viewer is instructed to count how many passes were made by the white shirt team. While the two teams are passing the ball back and forth, a person dressed as a gorilla, walked across the screen, beats his chest, and exits. The gorilla is on screen for 9 seconds. Half of the participants did not see the gorilla; it was as though the gorilla was invisible.

Eyewitness testimony can be influenced by various factors, such as the brief duration of exposure, presence of weapons, cross-racial identification challenges, time lapses, and the testing procedure itself. These elements contribute to the complexities and potential inaccuracies in facial recognition and memory recall, highlighting the importance of understanding and addressing these factors in legal and investigative contexts. For example, when a weapon is used during a violent crime, the eyewitness focus is often aimed at the weapon and consequently, they are unable to provide an accurate detailed description of the perpetrator. Researchers have also suggested that the issue of misidentification becomes more likely if the victim and perpetrator are of different races. (Meissner & Brigham, 2007)

The recommendations by James Doyle, co-author of the book Eyewitness Testimony: Civil and Criminal, and other researchers underscore the need for cautious handling of eyewitness testimony. Adapting procedures, such as choosing line fillers that match the verbal description of the perpetrator, instructing the witnesses that the perpetrator may or may not be present, having the photo array conducted by an administrator who does not know which person is the suspect, immediately recording the confidence levels of any choice that was made, and showing lineup members one at a time, sequentially, rather than using the traditional simultaneous method can enhance the reliability of identification processes. These adjustments acknowledge the potential pitfalls in eyewitness perception and aim to minimize misidentifications in criminal investigations.

Promoting education on the limitations of eyewitness evidence is crucial for fostering a more just legal system. Implementing programs for judges, law enforcement, lawyers, and jurors can enhance their understanding and application of scientific research, ultimately addressing issues related to eyewitness error.

In conclusion, while professionals in the legal and law enforcement fields strive for excellence, human error remains an inescapable reality. Understanding the root causes of these errors, particularly in the context of wrongful convictions, is vital for implementing reforms that uphold the principles of justice and safeguard individuals from the devastating consequences of miscarriages of the law.

  • Loftus, E. F. (1975). Leading questions and the eyewitness report. Cognitive Psychology, 7(4), 560-572.
  • Loftus, E. F., Miller, D. G., & Burns, H. J. (1978). Semantic integration of verbal information into a visual memory. Journal of Experimental Psychology: Human Learning and Memory, 4(1), 19.
  • Brigham, J. C., Bennett, L. B., Meissner, C. A., & Mitchell, T. L. (2007). The influence of race on eyewitness memory. In R. C. L. Lindsay, D. F. Ross, J. D. Read, & M. P. Toglia (Eds.), Handbook of eyewitness psychology, Vol. 2: Memory for people (pp. 257–281). Mahwah, NJ: Lawrence Erlbaum.
  • Makary, Martin (Professor), Daniel, Michael (Research fellow) Medical error – the third leading cause of death in the US BMJ 2016 353 doi: Published 03 May 2016) Cite this as: BMJ 2016;353:i2139

* Senior Instructor with John E. Reid and Associates

Permission is hereby granted to those who wish to share or copy this article. In those instances, the following Credit Statement must be included "This Investigator Tip was developed by John E. Reid and Associates Inc. 800-255-5747 /" Inquiries regarding Investigator Tips should be directed to Toni Overman