Discussing the use of Expert Evidence in Trial Essay

Adept grounds is going more established in the field of eyewitness testimony because jurymans are often puting undue trust on eyewitnesses. Jurors are being informed on the restrictions of eyewitness designation as this can play a immense significance within a tribunal instance ( Cunningham & A ; Tyrrell, 1976 ) .

subdivision on dependability and cogency of adept grounds

Expert psychological informants are called before the jury to supply their cognition of research and theories within the field of eyewitness testimony. They are non at that place to show ‘facts ‘ about the specific instance but instead supply scientific information of eyewitness histories that help the jury make determinations ( Vidmar & A ; Schuller, 1989, as cited in Leippe, 1995 ) . This procedure can present better eyewitness truth as the jurymans can measure the dependability and cogency of testimonies and establish their determinations from this ( Monahan & A ; Walker, 1988, as cited in Leippe, 1995 ) . However, Leippe ( 1995 ) stated that there is insufficiency in scientific research and theory as he argued that this field of research is non dependable because it can non be generalised to the “ existent universe ” and lacks ecological cogency. Some tribunals and several experimental psychologists have argued against research on eyewitness testimony as being scientific, as they have established that eyewitness research is non widely accepted as a scientific discipline as findings have non been by and large approved ( Egeth, 1993 ) .

Previous research on a study of 488 responses to expert witness inquiries and credibility was carried out. This produced deductions of dependability and cogency of adept grounds. It was found that the bulk of respondents stated that they would believe experts from their ain community as they were sensitive to the issue of adept informants being a “ hired gun ” which refers to expert sentiments that are non impartial due to being bias towards the party that called them ( Boccaccini & A ; Brodsky, 2002 ) . A bulk of respondents specified that they would believe experts who were non acquiring paid for their testimony ; this allows respondents to believe that the experts are supplying an honorable opinion and are non saying information on the footing of anticipating return ( Cooper & A ; Neuhaus, 2000, as cited in Boccaccini & A ; Brodsky, 2002 ) . In add-on to this factor, respondents conveyed a penchant for testimony from experts that have antecedently testified for the prosecution and defense mechanism instead than one or the other ( Boccaccini & A ; Brodsky, 2002 ) .

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A figure of instances have debated that adept testimony is merely “ common sense ” and this cognition can be made by the un-educated jurymans, and the lacks in the truth of designation can be conveyed to the jury over cross-examinations, and shutting statements ( Woller, 2003 ) .

A survey by Levett & A ; Kovera, 2008 indicate that there is a sensitization amongst jurymans on the cogency of initial adept research when opposing adept research is introduced to turn to the cogency of the initial adept research. Evidence was found that this procedure allows non-extreme opinions to be made by jurymans but will non straight affect significant determinations on the results of a instance. This shows incompatibilities when utilizing initial adept research because the survey illustrates that opposing experts give the sentiment that initial adept research is unsuitable to the instance. This suggests the inquiry on whether the rightness on holding an initial expert informant is needed at all as they often do non act upon juryman ‘s determinations.

Overall, eyewitness testimony dependability depends on many factors, in some instances it is dependable and in others it is non. Individual factors can lend to whether the information given is right or non.

Personal sentiment whether it would be appropriate to utilize experts in this instance

Adept grounds helps supply research and theory about well-known variables which can act upon memory and recalling of memory. Therefore by utilizing adept grounds in the instance of measuring eyewitness testimonies is important, as much research has supported the defects which can lend to misdirecting information. As a consequence of such a high dependence and impact of the justice ‘s determination of the eyewitness testimony in finding one ‘s life result, it is of import that all steps are put frontward in order to forestall a individual who is non guilty from traveling to prison.

On the other manus, I believe that there were a figure of variables within this instance that is deemed to be excessively complex to mensurate separately. I think that it is much harder to acquire an accurate history of the event itself when sing the variables in isolation. The theories are non established plenty to concentrate on the variables combined which could potentially give a more accurate history of the event.

If an expert informant was used for this instance, I believe that they would significantly impact the determination of the jury. They slightly take the function of the juryman and straight affect the credibleness of the eyewitnesses testimony. This should non be acceptable as an adept informant should merely be at that place to supply facts about certain pieces of grounds and non about specific variables within the instance.

Overview of psychological grounds that may be brought before the tribunal by the expert for the prosecution ( Guilty )

Around 20

Research states 3 highest truth degrees: sex tallness and racei

Freya remembered more detail-eyes-more accurate -watching and had more light more oppotunity

Detailed descriptions

Nature of event

The nature of the event can hold a profounding consequence on the informant ‘s future callback. Witnesss who experience a traumatic event tend to hold higher emphasis degrees. This enables them to hold a much elaborate memory as they frequently think about the event after it has happened. Because of the distressing nature of the event, it makes it harder for a informant to bury. All 3 informants within the instance experienced a signifier of force and therefore their degrees of rousing would hold increased. Harmonizing to research findings, this could heighten the truth of the description of the event and suspect ( Christianson, 1992 ) . Yuille and Cutshall ( 1986 ) besides found that higher emphasis degrees lead to better memories of events than do informants with lower emphasis degrees.

Assurance ( Meta-memory )

A informant that is confident when supplying their testimony to tribunal functionaries are normally more believed to be accurate ( Wise & A ; Safer, 2004 as cited in Krug, 2007 ) . A survey performed by Bradfield and Wells ( 2000, as cited in Bradfield & A ; McQuiston, 2004 ) found that a participant juryman who reads a testimony from a confident informant is said to of had a better position of the event compared to a informant whose assurance was low. Even when the jury has stated that ‘confidence ‘ is non an accurate determiner, there is grounds to believe that high assurance does let the jury to show a better rating of the informant ( Fox & A ; Walters, 1986 ) . Pratima Hussain conveyed a high degree of assurance when declaring her testimony as she stated that she ‘categorically ‘ knew that the suspect was the individual that pushed her to the land. She besides gave a really elaborate description of the arm. This may act upon the prosecution of the suspect by the jury because her assurance can be a immense forecaster of truth. Bell & A ; Loftus, 1989 besides established that when assurance is expressed, jurymans are impressed with that assurance which makes them more easy persuaded.

Number of Witnesss

Witnesss, who are at the same offense and place the same fishy under different conditions, are more likely to be accurate. A survey by Haber and Haber ( 2000 ) shown that if a informant provides a description of a suspect and so subsequently identifies them within a picture individuality parade, they are said to be 75 % accurate. If another informant, who was present at the same offense, provides a similar description of the suspect and besides identifies the same individual from the individuality parade, both of their designations are said to be 90 % accurate. This factor relates back to the instance since Pratima Hussain and Emanuel Hargreaves both gave a similar description of Kevin Clough and both identified him from the mug shots and individuality parade.

Overview of psychological grounds that may be brought before the tribunal by the expert for the defense mechanism:

Women ‘s seeing was discredited ( spectacless came off )

Pushed land


Less likely if realy old-age recogitionn

The nature of event

The consequence of rousing on eyewitness memory is now normally explored utilizing the Yerkes-Dodson jurisprudence ( 1908 ) which states that the connexion between rousing and public presentation is based on a U-shaped curve whereby really high or really low degrees of emphasis decreases the public presentation of the informant and that intermediate degrees of emphasis is when public presentation is at its best ( Deffenbacher, 1983 as cited in McCloskey & A ; Egeth, 1983 ) . Therefore in relation to the event being violent, stress degrees must hold been really high which can do disagreements in the eyewitness testimonies given.

Stress interferes with the ability of eyewitnesses to place a cardinal individual in a nerve-racking state of affairs ( Morgan et al, 2004, as cited in Wells, Memon & A ; Penrod, 2006 ) .

The high emphasis itself could be expected to take to a narrowing of the scope of perceptual focal point, as Easterbrook ( 1959 – some facts about arms ) has noted.

Mugshot induced prejudice

In this instance, 2 of the informants were required to transport out mugshot designation and a picture individuality parade. Research by Cutler et Al ( 1987, as cited in Ebbesen & A ; Konecni, 1997 ) has shown that exposure to mug shots after sing the suspect at the scene of the offense may make a hazard that the informant may go prejudice within the subsequent picture individuality parade. This is because the informant increases their ability to recognize a antecedently seen face. The informant may bring down a failure of memory due to old exposure of other mug shots and hence fail to place the existent suspect from the event ( Brown, Deffenbacher & A ; Sturgill, 1977, as cited in Deenbacher, Bornsteiny & A ; Penrod, 2006 ) .

as Garven, Wood and Malpass ( 2000, as cited in Hafstad & A ; Memon, 2004 ) found Retention of memory

The ability to take in information and keep it is a really of import factor to reflect on. Many surveies have shown that memory may deteriorate after an event occurs. There is more than one ground that keeping of an event may be lost, which can include post events that take over the memory of the original event or likewise, a informant being exposed to information from other informants ( Woocher, ( aˆ¦ . ) as cited in Baggett, 1975 – Memory for Explicit and Implicit Information in Picture Stories ) . Another ground may include bad experiences of a peculiar event that might extinguish memory from a informant because they choose non to retrieve it. Shapiro and Penrod ( 1986, as cited in Smith, Stinson & A ; Prosser, 2004 ) performed a survey on long vs. short holds and found that longer holds led to less right and more false designations. From this survey, it is clear to see that keeping plays an of import component when doing right designations. This is besides true of the Kevin Clough instance, as all of the informants were required to place the suspect from mug shots 2 yearss after the event occurred. They besides had to place the suspect from a picture individuality parade, 8 yearss after the event occurred.


A factor that can impact eyewitness perceptual experience is a term called an ‘event factor ‘ . This is when natural conditions within an event can impact the informant ‘s perceptual experience when an event occurs. It might look natural to believe that witnessing an event in good lighting conditions, may better perceptual experience compared to hapless lighting conditions. However, this is non the instance as research has found that different illuming conditions can be comparatively complex ( Woller, 2003 ) . Adaptation to visible radiation and dark has a important consequence on perceptual experience. It has been found that when witnessing an event in a dark status and so there is sudden alterations to a light status, or the opposite, the eyes are unable to to the full retrieve right off and perceptual experience is distorted. This is the cause of a chemical reaction go oning within the oculus between the rods and cones which generates a short experience of ‘blindness ‘ . In the instance of Kevin Clough, this can hold a profound consequence on Freya Ogden ‘s perceptual experience. On the eventide of January 12th, it would hold been dark outside and Freya reported that a security visible radiation shone on the wrongdoer as he ran past her. Consequently, her designation of the wrongdoer may be unjustified as a consequence of light version.

Cross-Race Designation

A major factor refering eyewitness designation is Cross-Race Identification. A jury may be alerted when sing the status of a informant ‘s race that is different to the race of the suspect and the truth of the designation. Research has found people from one race have great trouble placing people from a different race. This is because people that by and large socialise with other people from their ain racial group tend to absorb certain facial characteristics more easy compared to people from another racial group ( Malpass & A ; Kravitz, 1969 ) . Members of one race tend to province that members of a different racial group have less homogeneousness in the facial characteristics in relation to their ain racial group ( Goldstein, 1979 as cited in Smith, Stinson & A ; Prosser, 2004 ) . Ng and Lindsay ( 1994 ) stated that the more contact a individual has with people from a differing racial or cultural group, the ability to place suspects right will be greater. This issue might be a conducive factor sing the Kevin Clough instance because 2 of the informants, Pratima Hussain and Emanuel Hargreaves, are of a different racial group to the suspect. This could intend that their designation of Mr Clough may be priceless to the instance sing the factor of cross-race designation.

Individual factors – Age

Another factor which should be considered in conformity to eyewitness testimonies is age. Age is found to play a important function in eyewitness testimonies. All informants are seen to be vulnerable, nevertheless kids have been found to be the most vulnerable ( Bruck & A ; Ceci, 1999, as cited in Wells, Memon & A ; Penrod, 2006 ) . Children have been found to be susceptible to interviewer prejudice, as Garven, Wood and Malpass ( 2000, as cited in Hafstad & A ; Memon, 2004 ) found 50 % of kids who received positive support for describing wrong responses continued to reply “ yes ” to the deceptive information, whereas 5 % answered yes when no support was applied. This research suggests kids are easy misled with what they experienced from the event. Research has besides found a diminution in memory for aged informants. Cohen and Faulkner ( 1989 ) found aged topics were easy misled by false information. This states that expert eyewitnesses are important in instances where kids and aged informants are attesting. Research has besides found assurance and memory studies can easy be distorted in peculiar with vulnerable kids, as kids are believed to be excessively optimistic with their memory proficiencies ( Hafstad, Memon & A ; Logie, 2004 ) .

Weapon Focus

The presence of a arm can well bespeak to an eyewitness that a offense is go oning. The concentration on the arm itself can cut down the ability to absorb other information from the offense ( Loftus & A ; Messo, 1987, as cited in Mitchell, Livosky, & A ; Mather, 1998 ) . Weapon focal point is linked to arousal and Easterbrook ( 1959, as cited in Mitchell et al. , 1998 ) found that perceptual experience decreases as rousing degrees addition which is based on his/her cue use theory. The theory besides points out that the more intense the rousing is of an eyewitness, the bigger the decrease in perceptual cues. When a arm is seeable within a offense, the arm focal point consequence states that all focal point is pointed at the arm and perceptual cues such as the felon ‘s features are decreased. The instance of Kevin Clough is interesting because the victim Pratima Hussain was able to supply a elaborate description of the arm, and place features of the suspect right. Mrs Hussain was able to place the suspect ‘s age, race and oculus coloring material right. Research by Dehon and Bredart ( 2001 ) as cited inaˆ¦ has found that white people are able to do a more accurate age estimation for in-groups than out-groups. However, the truth of age estimations from people of other races that live or have lived preponderantly in a white state did non differ based on the race of the face.

Research was carried out by Anastasi & A ; Rhodes, 2006 as cited in Age Estimation of Faces on whether the age of the witness corresponds with the age of the suspect. Consequences found that age estimations are frequently bias towards their ain age scope. Research besides found that informants that are much older than the fishy exhibit poorer public presentation sing face acknowledgment Adams-Price, 1992 as cited in Evidence for an Own-Age Bias in Face. Therefore, there is a possibility that Pratima Hussain ‘s age estimation of the suspect could hold been incorrect and that she may hold guessed the age of the suspect.

Indicate what you consider to be the strongest grounds for both the prosecution and for the defense mechanism.


Defense mechanism

Retention of memory

It is clear that memory diminutions over a period of clip. I think this is an of import factor because the longer the length of clip between the larning experience and trial of designation, the likeliness that memory will diminish will be greater.


selective attending, rehabilitative memory, short exposure continuances, vantage point, suggestion