Eyewitness testimony

Eyewitness testimony is the account a bystander gives in the courtroom, describing what they perceived happened during the specific incident under investigation. Ideally this recollection of events is detailed, however this is not always the case. This recollection is used as evidence to show what happened from a witness' point of view. Memory recall has been considered a credible source in the past, but has recently come under attack as forensics can now support psychologists in their claim that memories and individual perceptions are unreliable; being easily manipulated, altered, and biased. Due to this, many countries and states within the USA are now attempting to make changes in how eyewitness testimony is presented in court. Eyewitness testimony is a specialized focus within forensic psychology.

Reliability

The reliability of eyewitness testimony has been questioned by psychologists since the beginning of the 20th century.^[1] However, many early studies on the matter were regarded as insufficient. This questioning of its credibility began with Hugo Munsterberg, who first developed the field of Forensic Psychology. He specifically doubted the reliability of perception and memory in "On the Witness Stand." Interrogation was mentioned as an issue because of its intimidating methods. Through this he developed an early version of the lie detector. There was a torn reaction to his ideas; while the legal arena was in stern disagreement, it was popular among the public.^[2] It was not until forensic DNA testing began exonerating innocent people d 52 of the first 62 DNA exoneration cases involved eyewitness testimony.^[3] The Innocence Project reports eyewitness misidentification occurs in approximately 75% of convictions that are overturned.^[4] In the USA, juries are responsible for assessing the credibility of witness testimony presented in a trial.^[5] Research has shown that mock juries are often unable to distinguish between a false and accurate eyewitness testimony. The confidence level of the witness is often seen by jurors to correlate with the accuracy of their testimony. An overview of this research by Laub and Bornstein shows this to be an inaccurate gauge of accuracy.^[6] Another reason why eyewitness testimony may be faulty is due to an eye witness's memory being influenced by things that they might hear or see after the crime occurred. This distortion is known as the post-event misinformation effect (Loftus and Palmer, 1974). After a crime occurs and an eyewitness comes forward, law enforcement tries to gather as much information as they can to avoid the influence that may come from the environment, such as the media. Many times when the crime is surrounded by much publicity, an eyewitness may experience source misattribution. Source misattribution is when a witness is incorrect about where or when they have the memory from. If a witness cannot correctly identify the source of their retrieved memory, the witness is seen as not reliable.

While some witnesses do see the entirety of a crime happen in front of them, there are some that only witness part of a crime. These witnesses are more likely to experience confirmation bias. Witness expectations are to blame for the distortion that may come from confirmation bias. For example, Lindholm and Christianson (1998)found that witnesses of a mock crime, who did not witness the whole crime, nevertheless testified to what they expect would have happened. These expectations are normally similar across individual due to the details of the environment.

Research

Research on eyewitness testimony looks at systematic variables or estimator variables. Estimator variables are characteristics of the witness, event, testimony, or testimony evaluators. Systematic variables are variables that are, or have the possibility of, being controlled by the criminal justice system. Both sets of variables can be manipulated and studied during research, but only system variables can be controlled in actual procedure.^[1]

Estimator variables

Age

Suggestibility is the term used when detail that comes after the actual event is incorporated into the memory of the event itself. Similar to a hindsight bias, it further constructs the memory with information gained after the event had already ended. Among children, suggestibility is very high. Their young age and developmental stage cause them to be more easily influenced by leading questions, misinformation, and other post event details. Especially among the preschool age, children fall victim to suggestions without the ability to solely focus on the facts of what happened.^[7]

Reconstructive memory

Many of the early studies of memory demonstrated how memories can fail to be accurate records of experiences. Because jurors and judges do not have access to the original event, it is important to know whether a testimony is based on actual experience or not.^[8]

In a 1932 study, Frederic Bartlett demonstrated how serial reproduction of a story distorted accuracy in recalling information. He told participants a complicated Native American story and had them repeat it over a series of intervals. With each repetition, the stories were altered. Even when participants recalled accurate information, they filled in gaps with false information. His work showed long term memory to be adaptable.^[9] Bartlett viewed schemas as a major cause of this occurrence. People attempt to place past events into an existing representations of the world, making the memory more coherent. Instead of remembering precise details about commonplace occurrences, a schema is developed. A schema is a generalization formed mentally based on experience.^[10] The common use of these schemas suggests that memory is not an identical reproduction of experience, but a combination of actual events with already existing schemas. Bartlett summarized this issue, explaining

[M]emory is personal, not because of some intangible and hypothetical persisting ‘self ’, which receives and maintains innumerable traces, restimulating them whenever it needs; but because the mechanism of adult human memory demands an organisation of ‘schemata’ depending upon an interplay of appetites, instincts, interests and ideas peculiar to any given subject. Thus if, as in some pathological cases, these active sources of the ‘schemata’ get cut off from one another, the peculiar personal attributes of what is remembered fail to appear.^[11]

Further research of schemas shows memories that are inconsistent with a schema decay faster than those that match up with a schema. Tuckey and Brewer found pieces of information that were inconsistent with a typical robbery decayed much faster than those that were schema consistent over a 12 week period, unless the information stood out as being extremely unusual. The use of schemas has been shown to increase the accuracy of recall of schema-consistent information but this comes at the cost of decreased recall of schema-inconsistent information.^[12]

Misinformation effect

Elizabeth Loftus is one of the leading psychologists in the field of eye witness testimony. She provided extensive research on this topic, revolutionizing the field with her bold stance that challenges the credibility of eyewitness testimony in court. She suggests that memory is not reliable and goes to great lengths to provide support for her arguments. She mainly focuses on the integration of misinformation with the original memory, forming a new memory. Some of her most convincing experiments support this claim:

1. In one of her experiments, Loftus demonstrates that false verbal Information can integrate with original memory. Participants were presented with either truthful information or misleading information, and overall it showed that even the false information verbally presented became part of the memory after the participant was asked to recall details. This happens because of one of two reasons. First, it can alter the memory, incorporating the misinformation in with the actual, true memory. Second, the original memory and new information may both reside in memory in turn creating two conflicting ideas that compete in recall.^[13]
2. Loftus conducted more experiments to prove the reliability of expert psychological testimony versus the accepted basic eyewitness testimony. It was found that jurors who hear about a violent crime are more likely to convict a defendant than of one from a nonviolent crime. To reduce this tendency for a juror to quickly accuse, and perhaps wrongly accuse, choosing to utilize expert psychological testimony causes the juror to critically appraise the eyewitness testimony, instead of quickly reaching a faulty verdict.^[14]
3. Also, it has been shown that intelligence and gender has a role in the ability of accurate memory recall. Participants were measured in eyewitness performance in two areas: 1) the ability to resist adding misinformation to the memory and 2) accuracy of recalling the incident and person. It showed that when a woman was recalling information about a woman, the resistance to false details was higher and the recall was more accurate. If a man was recalling an incident involving a man, similarly the recall was more accurate. However, when dealing with opposite genders, the participants gave into the suggestibility (misinformation) more easily and demonstrated less accuracy.^[15]
4. Facial recognition is a good indicator of how easily memories can be manipulated. In this specific experiment, if a misleading feature was presented, more than a third of the participants recalled that detail. With a specific detail, almost 70% of people claimed that it had been there, when it had not been present.^[16]

Repeatedly, Loftus conducts experiments to support the unreliability of eyewitness testimony, based on her argument that memories can be altered.

Systematic variables

Type of questioning

As early as 1900, psychologists like Alfred Binet recorded how the phrasing of questioning during an investigation could alter witness response. Binet believed people were highly susceptible to suggestion, and called for a better approach to questioning witnesses.^[17]

Crombag, Wagenarr, and Koppen (1996) built on this and other research by studying the real life situation of El Al Flight 1862 and eyewitness testimony about the event. In October 1992, a plane leaving Amsterdam airport lost power in both engines, shortly after take off. The crew attempted to return to the airport but were unable to maintain flight and crashed into an 11 story apartment building. Though no cameras caught the moment of impact on film, many news stations covered the tragedy with footage taken after impact.^[18] Ten months after the event, the researchers interviewed people about the crash. According to theories about flashbulb memory, the intense shock of the event should have made the memory of the event incredibly accurate. This same logic is often applied to those who witness a criminal act. To test this assumption, participants were asked questions that planted false information about the event. Fifty-five percent of subjects reported having watched the moment of impact on television, and recalled the moment the plane broke out in flames-even though it was impossible for them to have seen either of these occurrences. One researcher remarked, "[V]ery critical sense would have made our subjects realize that the implanted information could not possibly be true. We are still at a loss as to why so few of them realized this."^[19] This research raised questions as to the accuracy of flashbulb memories and highlighting how witnesses could be manipulated through leading questions.

A survey of research on the matter confirm eyewitness testimony consistently changes over time and based on the type of questioning.^[20] The approach investigators and lawyers take in their questioning has repeatedly shown to alter eyewitness response. One study showed changing the adverb slow to fast in asking participants, "How slow was the car going?" after viewing video footage of a car accident increased their overall estimation of the car's speed.^[21]

Improving eyewitness testimony

Law enforcement, legal professions, and psychologists have worked together in attempts to make eyewitness testimony more reliable and accurate. Geiselman, Fisher, MacKinnon, and Holland saw much improvement in eyewitness memory with an interview procedure they referred to as the cognitive interview. The approach focuses on making witness aware of all events surrounding a crime without generating false memories or inventing details. In this tactic, the interviewer builds a rapport with the witness before asking any questions. They then allow the witness to provide an open ended account of the situation. The interviewer then asks follow up questions to clarify the witness' account, reminding the witness it is acceptable to be unsure and move on.^[1] This approach guides the witness over a rigid protocol. When implemented correctly, the CI showed more accuracy and efficiency without additional incorrect information being generated.^[22]

Currently, this is the U.S. Department of Justice's suggested method for law enforcement officials to use in obtaining information from witnesses.^[23] Programs training officers in this method have been developed outside the U.S. in many European countries, as well as Australia, New Zealand, and Israel.^[24]

While some analysis of police interviewing technique reveals this change towards CI interviewing is not put into effect by many officials in the U.S.A. and the U.K., it is still considered to be the most effective means of decreasing error in eyewitness testimony.^[1][25]

Procedural reforms

Experts debate what changes need to occur in the legal process in response to research on inaccuracy of eyewitness testimony.

Jury guidelines

It has been suggested that the jury be given a checklist to evaluate eyewitness testimony when given in court. R. J. Shafer offers this checklist for evaluating eyewitness testimony:

• How well could the eyewitness observe the thing he reports? Were his senses equal to the observation? Was his physical location suitable to sight, hearing, touch? Did he have the proper social ability to observe: did he understand the language, have other expertise required (e.g., law, military)?
• When did he report in relation to his observation? Soon? Much later?
• Are there additional clues to intended veracity? Was he indifferent on the subject reported, thus probably not intending distortion? Did he make statements damaging to himself, thus probably not seeking to distort? Did he give incidental or casual information, almost certainly not intended to mislead?
• Do his statements seem inherently improbable: e.g., contrary to human nature, or in conflict with what we know?
• Remember that some types of information are easier to observe and report on than others.
• Are there inner contradictions in the testimony? ^[26]

Judge guidelines

In 2011, the New Jersey Supreme Court created new rules for the admissibility of eyewitness testimony in court. The new rules require judges to explain to jurors any influences that may heighten the risk for error in the testimony. The rules are part of nationwide court reform that attempts to improve the validity of eyewitness testimony and lower the rate of false conviction.^[27]

See also

• Anecdotal evidence
• Confabulation (false memory)
• Eyewitness identification
• Legal psychology
• Forensic psychology
• Mistaken identity

References

External links

• Evidence-based justice: Corrupted memory, Nature, 14 Aug 2013