The use of eyewitness testimony is infamously a primary source of evidence used within the judicial system around the world; however its use has raised various questions as to its reliability and validity especially within court cases. This essay explored first of all, the biological factors of memory and recollection of memories within the human brain. Memories are believed to be stored and processed within the hippocampus part of the brain where it goes through the multi-store model (Atkinson and Shiffrin, 1968). This is where danger of the reliability of memory occurs. It was argued that eyewitness testimony is a reliable form of evidence especially with its validity in terms of the events leading up to the use of EWT; what is deemed important information is believed to be remembered more clearly. Sigmund Freud (1920) suggested that memories can only be retrieved by encouraging remembering past episodes and re-instating these ‘past memories’ into their consciousness. Psychologists Nibett and Ross (1980) quoted that the reason why eyewitness testimony is persuasive is that it influences the jury on a deeper level. However, eyewitness testimony posed more disadvantages than advantages with the various factors that affect it such as weapons focus in incidents involving weapons which cause distractions and loss of memories. The primary psychologist that tested the use of memory was Elizabeth Loftus who conducted various experiment to test this, such as the Automobile Destruction experiment in the 1970’s. After having collated all the arguments together, it was suggested that improvements must be made in order to improve the quality of eyewitness testimony; these included the legal system and police force’s involvement in collating information as quickly as possible.
The most imperative form of evidence when investigating a crime is the honesty of witnesses on trial, the application of eyewitness testimony. Though the use of eyewitness testimony by juries is considered most valuable, the question of fallibility of witness statements poses various problems and issues. Eyewitness testimony has been a thriving aspect of the Criminal Justice System, an incredible amount of research into this element of cognitive psychology questions the reliability of people’s memory especially using it as evidence to determine the outcome of the trial and convictions. Research into the reliability of evidence, often referred to as “witness psychology” is renowned as being the longest established area of law and psychology, dating back to the beginning of the 20th century. 
The area of eyewitness testimony has always posed a problem with reliability and the effectiveness of human memory. Human memory is described by cognitive psychologists Atkinson and Shiffrin (1968)  as a three stage theory in which memory is modelled in, this memory stage model is called the ‘Multi-Store Model’. The Multi-store model theory consists of the memory being divided into three stages, the first stage being the sensory store, the second stage is the short term memory (working memory) and the third being long term memory. The transfer of information from one store to another is controlled by the process of attention and rehearsal of memories. One of the most critical assumptions made by cognitive psychologists is that the human mind has a limited capacity for processing information. Therefore, any external information that the environment consists of is often very difficult for the human mind to assimilate and process; so people are selective about what information is to be retrieved and this is otherwise known as attention, where some information is assimilated while other pieces are ignored.
The first stage of the multi-store model, the sensory store, is where the information from the senses (iconic, echoic, tactile, olfactory and gustatory), is transferred into but this is only for a very short period of time. The initial information retrieved by the senses is then transferred into the short term memory store; this is transferred through attention given to the information transferred from the senses involved. When the information has been transferred into the short-term memory store, this is the store concerned with forgetting information and this information is ultimately lost entirely. Therefore, for information to be remained in the memory, from the short term store into the long term store, the information must be rehearsed. Rehearsal is the cycling of information through the memory, this rehearsal of memory can be carried out in two different methods.
Therefore this essay will investigate whether the application of eyewitness testimony statements is a reliable form of evidence to be used by the judicial system. Furthermore, this essay will argue whether eyewitness testimony is ideal to use as one of the most important pieces of evidence to use or whether the application of eyewitness testimony is fallible. After comparing for and against the reliability of eyewitness accounts, an evaluation will be drawn over how eyewitness testimony can be improved to an extent where it can be further accurate. This essay will explore the elements of eyewitness testimony and how these factors can determine whether an eyewitness account is accurate. These elements include the effect of weapon focus on witness memory, how leading questions can manipulate witness statements and recollection of memory, reconstructive errors of memory and the application of psychological experiments when exploring the function of these elements on the human memory. The application of the eyewitness testimony includes multiple formal questioning sessions with witnesses on trial, taking statements of the events witnessed and witnesses appearing in court with the jury. The issue of integrity when applying eyewitness testimony accounts is delegated to the jury, who are assigned the role of determining the judgement of whether the eyewitness statements are fallible or reliable  . The use of eyewitness testimony has a profound and compelling effect on the outcome of a trial and conviction, and this is why an accurate eyewitness testimony is needed in order to gain justice.
The Aspects of Eyewitness Testimony
As a consequence of the limitations of information processing in the human mind, witness statements need to be reviewed for accuracy and if any external factors of either the environment or the function of memory may have affected the outcome of the witness account  . Quite often, when the memory cannot recall the entire incident or situation, it may result in the unknown areas being replaced by events that may never have took place in reality but the mind may perceive as a potential occurrence and therefore causes fallibility in the eyewitness testimony. In essence, the memory may fill in gaps where it fails to recall what may have happened  . Many factors affect eyewitness memories which are illustrated below:
Interference of Memory Processing: The period of time that has lapsed between the witnessing of the incident and the questioning of the eyewitness can determine the amount of information that the witness can recall. On the other hand, interference which is the loss of old stimuli as a result of new information can also subsequently reduce the accuracy of eyewitness accounts. 
Leading Questions in Witness Interviews: A leading question in its form or content, suggests to the witness being interviewed what answer is desired or leads them to the desired answer. Some questions can often be made more suggestive than others and these questions the legal concept of a leading question. The main pioneer for investigating the consequences of particular leading questions was Elizabeth F. Loftus in 1974. 
Schemas: The human mind has evolved its memory capacity and the ability to remember certain aspects by organising information into categories, otherwise known as schemas  . Schemas help organise memories that can consist of familiar people, objects and situations and allow people to understand and act appropriately to whatever is encountered.
Arousal, Anxiety and Violence Distraction: Quite often, cognitive psychologists have questioned the poor recall of eyewitness accounts is primarily a result of where their attention is focused upon. A possible reason for arousal, anxiety and violence distraction could be that a violent incident, with the use of weapons, draws the focus of the witness’s attention away from who is causing this anxiety, which results in little or no processing of other information. 
Weapon Focus: When a witness views a crime in which a weapon is used as a method of violence and distraction, the weapon achieves its purpose in distracting the attention of those witnessing the crime. The distraction affects the witness’s attention due to the potential threat of violence9.
External Influences: Quite often, external influences can affect the accuracy of eyewitness accounts, especially if the media has been influencing the events that have taken place. The witness may re-interpret their witness statements to match what the media has claimed may have existed or happened. Apart from the media, other external influences may include other witness accounts of what happened and/or the type of environment that the situation may have occurred in, e.g. in darkness, low-lit room etc.
Conformity: Through the questioning process that witnesses must endure, group questioning in particular, gives into reason the reliability of witness recollections as they may conform in order to fit each other’s interpretation of what happened.
Reliability of Eyewitness Testimony
The use of eyewitness testimony has provided crucial evidence that can often lead to the identification and arrest of a criminal suspect or a hazardous event can be avoided. Eyewitness testimony impacts strongly upon the trial process and the verdicts that are given by the jury are quite often influenced heavily by eyewitness accounts. Stern and Dunning, 1994  quoted that eyewitness testimony is perhaps ‘the most compelling types of evidence presented to police investigations and criminal trials’.
Although the human memory and its information processing ability, has substantial amounts of limitations that can lead to invalidity and inaccuracy, it does however, demonstrate a unique ability to process information where the acquired stimulus information is stored. The human mind can potentially hold millions of pieces of information, though not all at once, which when acquired by the brain can be reinstated and remembered. The memories that the mind deems as important for growth and use consistently is life are episonic which represents the episode of the memory where as certain skill or piece of information; semantic which identifies what that piece of information consists of and what it is and finally procedural which processes who that information is to be used or handled. For example, teaching a child how to read a book at a particular age is episonic, knowing what a book is, is semantic and how to read the words in a book would be procedural. 
The process of information being transferred from the short term memory into the long term memory was an experiment conducted by psychologists Welch and Burnett in 1924. The experiment was to test the theory of the ‘serial position curve’ where it consisted of the subjects being presented with a list of 16 words in which they had to recall in order. The results of this experiment, illustrated the serial position curve in which the recollection of words and the results of the experiment were graphed and this illustrated a curve effect were the last recalled words were remembered best whereas the words in the middle of the recall were remembered poorly.
Cognitive psychologist, Sigmund Freud believed that memories were allocated in the brain  . Freud referred to these memories as “true memories” and described that they lay deep in the unconscious element of the brain, where they lay undisturbed as a factor of surface mental activity. Freud insisted that these memories were never lost or forgotten as they are “only inaccessible and latent, having become a part of the unconscious”  . For these memories to be accessed, Freud promoted the technique free association. By encouraging witnesses to reminisce about past episodes that have occurred within their lives, Freud insinuated that they could reinstate long-forgotten yet important memories from their past into their consciousness. However, it can be argued that the “true memories” that Freud insisted exist in the human sub-conscious are in fact potential complex blendings of both fact and fiction. Memory is an extremely fragile aspect of the human mind that can potentially be supplemented, altered and reconstructed by external stimuli that can question an event that may never have occurred.
However, it is argued that the human mind is capable of remembering significant pieces of information that is considered vital and important. This is considered one of the key factors in which juries do consider eyewitness testimony accounts as a vital piece of evidence. Psychologists Nibett and Ross, 1980 quoted that the reason why eyewitness testimony is persuasive is that “vivid testimonies have a strong impact on observers” so this conclusively means that they are easier to remember especially upon the jury  . Though the potential invalidity of eyewitness accounts is extensive, error made in witness accounts are extraneous when the observers are able to distinguish between accurate and inaccurate witnesses  . However, there may be a possibility that the eyewitness account is accurate but leading questions by the criminal investigation team may provoke the memory to be changed to fit the question or the most relevant and fitting answer  .
The Unreliability of Eyewitness Testimony
The malleability of eyewitness accounts demonstrates the excessive inaccuracy of it being used as a vital evidential piece in the courts and criminal justice system. Many hypotheses have been established that suggest reasons for the valued use of eyewitness testimony. Saunders et al believe that jurors tend to place too much faith in eyewitness testimonies; however the problem lies with whether eyewitness testimony is a reliable source of evidence to use  . The inaccuracy of witness accounts is demonstrated by the various aspects that intercept with each other and substantiate hesitation for its use as evidence.
The use of leading questions can quite often alter information/intelligence or can quite often misinterpreted accounts to match the information that the witness has been presented with. An experiment conducted by Elizabeth Loftus and John Parmer illustrates the interaction between language and memory in 1974  . The reconstruction of an automobile destruction consisted of two experiments in which subjects were shown films of automobile accidents. After the observation, the subjects were then asked questions about the events that occurred in the films; “How fast were the cars going when they smashed into each other?” The use of the word “smash” demonstrated higher estimations in the speed of the car as opposed to other verbs used in place of ‘smash’ such as ‘collided, bumped, contacted and hit’. When the experiment was repeated a week later, the subjects who received the word ‘smashed’ were more likely to agree to the question asked “Did you see any broken glass?” even though there was no recollection of broken glass within the video. These results highlight the theory that the questions asked in relation to an event can result in a reconstruction of a witness’s memory of that event.
Though witness memory is quite often inaccurate in that they fail to distinguish the events that had occurred, quite often, the human memory can remember erroneous events and details that may be introduced by third party interference. In the 1970’s, Elizabeth Loftus conducted an experiment to demonstrate how third party interference can invalidate witness accounts by introducing false facts. Subjects were shown a slideshow of a car at an intersection with either a “yield sign” or a “stop sign”. The experimenter then asked the participants questions which falsely used the word “stop sign” instead of “yield sign” which is what was actually shown in the slideshow. The results indicated that subjects remembered seeing the false image; the introduction of false cues altered the memory of the participants in the experiment.
Bartlett conducted an experiment in which he read a story “The war of the ghosts” out loud to a group of participants where he concluded that participants attempted to fit the story into their western schemas and as a result, distorted it during recall  . This showed that they were not recalling the information exactly as it had been presented to them, but were making assumptions at the story, based on their own understanding. This correlates with what a witness may assume a criminal or crime scene may look like and therefore use this to describe the suspected. Schemas are an effective method of processing and encoding information  . The idea of schemas were originally established by Frederick Bartlett in the 1930s which involved a large number studies in which he showed ways in which participants made sense of whatever they were shown affects the way they recall it later  . For example, in one of his studies, Bartlett showed participants unfamiliar line drawings and instructed them to memorise it. Bartlett then asked his participants to talk aloud at the same time as memorising the picture. He found that different participants made sense of the figures in different ways. Later in the experiment, the participants were asked to draw the figures as they remembered them and Bartlett discovered that the schemas which they established during their initial encoding influenced their recall. Therefore, schemas may influence what witnesses may define what a criminal looks like or behaves like and this may influence their account of events.
Through the questioning process that witnesses must endure, witnesses can either be questioned on a one-to-one basis where the interviewer questions the witness independently or witnesses can be questioned as a group if the incident has been witnesses by multiple people. In particular, group questioning which gives into reason the reliability of witness recollections as they may conform in order to fit each other’s interpretation of what happened. This conformity can purposely invalidate information as the witness does not want to be isolated from the events that the other witness’s describe as having happened. This subjective information again affects the testimony because false information is being interpreted is invalid due to conformity of information.
The “weapons focus” effect  perceives to be a result of the witness’s attention being predominantly directed towards the weapon, resulting in diversion of attention away from the situational aspects and the criminal suspect. When a witness views a crime in which a weapon is used as a method of violence and distraction, the weapon achieves its purpose in distracting the attention of those witnessing the crime. The distraction affects the witness’s attention due to the potential threat of violence. Although an incident has occurred, the attention of the witness is primarily upon the weapon so they are not observing the rest of the incident or the person who is posing the threat and this causes the witness to have lack of information about the incident. This area of eyewitness psychology is known as weapon focus; unfortunately this distraction results in a very poor eyewitness testimony as the witness is unable to recall events and descriptions. Unfortunately, most crimes involve the use of a weapon as a vulnerability tool, which in essence causes the stress and anxiety levels of the witness to rise and therefore will fail to encode and remember vital information.
Eyewitness inaccuracy may also be a result of errors that occur within the memory process; the memory is divided into three distinct stages of processing: encoding, storage and retrieval. The occurrence of errors is very likely at any particular stage within the memory processing stages. Acquiring information or otherwise known as encoding is illustrated within the Yerkes-Dodson principle which according to its theorists, an increase in arousal improves performance up to a certain point. Once arousal has passed the critical point which is otherwise known as the optimum, performance tends to decline and these results in poorer memory performance. So, in essence when a person is moderately aroused, the information is encoded best as opposed to extreme arousal or stress where the information is lost or encoded insufficiently. The Yerkes-Dodson theory  demonstrates that if a witness observes a crime that is substantially violent and/or makes the witness experience high levels of fear and anxiety, they are less likely to remember any significant levels of information because of the extreme stress which results in encoding of information inaccurate. This conclusively makes their eyewitness account unreliable because they fail to remember any substantial amounts of information and detail of what happened and of the perpetrator.
The question of witness account accuracy raises questions about whether the time after the incident occurred, if the account is still valid as evidence because quite often, large amounts of time and substantial interference can deteriorate the information from memory. This deterioration refers to the loss of stimulus information as a result of passed time. The amount of time that has lapsed between the occurrence of the event and the questioning and testimony of the witness can quite often determines the amount of information the witness can recall  . This interference is due to the loss of old stimulus information caused by new stimulus information; this can also reduce the accuracy of eyewitness accounts. People are more likely to overestimate the duration of brief events but on the other hand underestimate the duration of prolonged events (Penrod, Loftus and Winkler, 1982). Other psychological research has demonstrated that the presence of a weapon also reduces the accuracy of eyewitness accounts.
Evaluation of Eyewitness Testimony
Taking into consideration the flaws in which eyewitness accounts may consist of, which effectively invalidates the testimony, these flaws can be avoided by both the eyewitness and the criminal justice system that use the accounts as a form of evidence.
Most importantly, the way in which witness accounts are handled is vital in establishing a valid eyewitness testimony with as much ‘truth’ as possible. The interviewing process which is conducted by the criminal justice system i.e. police, courtroom judges, need to be done in a careful and delicate way so that there is no decay or deterioration of information. Though the memory of the witnesses may differ, depending on age and memory capacity, quite often the initial first few hours after the occurrence of an incident is vital in collecting as much valid information as possible. So, the interviewing of witnesses should be conducted right after the incident when possible to avoid any decay of information and/or third party interference.
In terms of the actual interviewing process, the use of leading questions should entirely be avoided unless the witness has mentioned specific events or descriptions which would not invalidate information as it has been confirmed by the witness. Leading questions  can quite often add new information that the witness may not have known about and will therefore mention ‘false’ information in order to fit their account with what is evidently known by the police. Specific questions that can be used in the interviewing process may help the witness to run through their track of events which in some circumstances reveal any recollection of events without any external influence.
Quite often through the criminal investigation, the witness needs to be interviewed many times to establish the course of events and important descriptions, whether this is through the crown prosecution trial or by the police. If later eyewitnesses need to be interviewed, they should be able to recall as much information that they reported initially, avoiding any extra information that they may have picked up from third party interference. So in essence, there is no uncertain information but information that the mind has remembered and rehearsed within their memory and indicates a positive recollection of events.
Though no control can be given to what eyewitnesses will focus on and concentrate entirely on, measures on how information is collected can partially help to distinguish between valid and ‘false’ information within accounts.
It can be concluded that the use of eyewitness testimony will also be used as a vital source of evidence by the criminal justice system for years to come. Eyewitness testimony can hold vital pieces of information that cannot be retrieved from any other source, without eyewitness testimony, the police would find it incredibly difficult to discover any potential clues and evidence of what happened or description of what the perpetrator physically looks like. Criminal cases in which there is not eyewitnesses to give evidence are usually those cases which find it incredibly hard to convict the guilty so have to rely upon other physical evidence such as CCTV, DNA, fingerprints etc.
However, the use of eyewitness accounts seems to create a lot of doubt in whether it is a reliable source of evidence to be used because its accuracy is questioned based on interpretation. The use of leading questions and third party interference can decay any initial recollection of events that the eyewitness may have believed to have happened. But the human memory has flaws within itself regardless of extra information that can falsify or invalidate the recollection of what occurred and why.
The initial pioneer of evaluating eyewitness evidence, Elizabeth F. Loftus  highlights the flaws of eyewitness accounts and of the human memory. The conclusions in which Loftus has discovered were advantageously used to improve quality of interviews and valid eyewitness accounts but unfortunately cannot eliminate all invalid information.
So, in essence, the question as to whether eyewitness testimony is a reliable source of evidence still remains unclear on the basis that it is vital evidence which is needed to collate important information. However, its reliability is questioned in terms of validity and how much the witness is able to accurately recall all pieces of information especially having experienced high amounts of anxiety and stress. Eyewitness testimony will always remain a vital source of evidence but its use should be delicately considered to avoid any false information or invalid convictions.