Making A Case

When someone witnesses a crime, their testimony is important because it counts as evidence. Therefore this topic is about establishing credible eye witness and investigating the validity and reliability of eyewitness testimony. It also looks at how it can be improved. 

- Recognising faces 

- Factors influencing recognition 

- The cognitive Interview 

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  • Created on: 31-01-13 08:47

Making a Case- Interviewing Witnesses

When someone witnesses a crime, their testimony is important because it counts as evidence and it is crucial when the Judge and the Jury reach a verdict. Therefore this topic is about establishing the processes of gaining credible eye witness and investigating the validity and reliability of eyewitness testimony. It also looks at how it can be improved. 

- Recognising faces 

- Factors influencing recognition 

- The cognitive Interview 

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Making a Case- Recognising Faces

Recognising Faces 

Being able to accurately identify a face is key to many convictions. There have been scenarios whereby people have been unjustly convicted because a witness recognised their face and picked it out of a suspect line up. Our ability to recognise faces if highly fallible and since it holds such great importance during a case, it is important that the accuracy of eye witness when recognising faces or picking out a suspect is more reliable. 

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Making a Case- Recognising Faces

Bruce et al 'The importance of external and internal features in facial recognition' 

Aim: To investigate the relative recognisability of internal and external features in facial recognition (Internal features are, eyes, brows, nose and mouth while external features are head shape, hair and ears). 

Method: Lab Experiement 

Experiment 1 

  • 30 staff and students (15 male and 15 female) of Stirling University (Scotland). Independent design measure with three conditions
  • Participants given pictures of 10 celebrities and asked to match the correct composite image to the celebrity from the 40 composites given
  • Group 1 had complete composites 
  • Group 2 had composites containing only internal features 
  • Group 3 had composites containing only external features

Each face was clean shaven and spectacles were avoided (Control/ Standardised procedure)

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Making a Case- Recognising Faces


  • 42% of whole composites and those of external features were sorted correctly 
  • In comparison only 19.5% of internal features composites sorted correctly

Experiment 2 

Participants: 48 students (27 male and 21 female) from Stirling University 

Procedure: Lab experiment. This experiment used a photo array (line up) and the task was to identify the celebrity composite from the array which also included distracter foils. Tested individually and randomly assigned to easy internal or external features or hard internal or external features. The composites were composed of either external or internal features. 


  • External features identified 42% of the time, compared to 24% for internal features
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Making a Case- Recognising Faces


Participants perfomed at just above chance level for internal features. They performed equally well with whole composites and external features. This shows that external features are more important for facial recognition and that faces are processed holistically. This has implications for facial reconstructions which involve witnesses picking internal features from a book as the reliability of this method seems questionable. Newer face reconstruction software takes these into account, E-FIT and EvoFIT both change faces holistically and are used by the police when asking witnesses to recognise suspects. 


  • Usefulness 
  • Ecological Validity 
  • Strengths and Weakness of a Lab Experiement 
  • Psychology as a science (cause and effect/ validity)
  • Strengths and Weakness of Quantitative Data gathered 
  • Reliability, Reductionism, The study illustrates cognitive approach 
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Making a Case- The Weapon Effect

This section looks at factors that influence identification and it will specifically be looking at weapon effect. Weapon focus refers to the concentration of a witness's attention on a weapon which results in them having difficulty recalling other details of the scene and identifying the perpetrator of the crime. It is believed that the stress of being in the presence of a weapon causes the witness to focus on the weapon and to subsequently have difficulty identifying facial features of the suspect. Pickel suggests it is the unusualness of the weapon that causes this effect while Loftus suggests it is the fear created by the weapon. 

Stages of memory 

  • Attention/ Accuisition: Witnessing the incident and the subjective interpretation of the event 
  • Retention: Period of time while waiting to give evidence 
  • Recollection: Giving Evidence 
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Making a Case- The Weapon Effect

Elizabeth Loftus et al 'Weapon Focus' 

Aim: To provide support for the weapon focus effect when witnessing a crime 

Participants: 36 students (aged 18-31) from the University of Washington, recruited via advertisements, paid $3.50 and the other participants were psychology students who were given extra credits for participating. 

Procedure: Lab experiment, participants were shown 18 slides of a series of events in a restaurant. For both groups the slide was the same except for one slide. This slide was the independent variable. In the control group the second person in the queue hands the cashier a cheque while in the experimental group, the person hands the cashier a gunThe dependent variable was the recognition of that person which was measured in two ways.

  • Firstly by a multiple choice questionnaire.
  • Secondly the participants were shown 12 photos in random sequence and asked if the person was the suspect and for them to rate how confident they were of their identification. 
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Making a Case- The Weapon Effect

  • They also used technology to measure the participant's eye fixation on the cheque or the gun. 


  • Answers to the questionnaire showed no significant difference between the group 
  • For the photo sequence, the control condition with the cheque made a correction identification of the suspect 39% of the time while in the experimental condition, correct identification was made 11% of the time- a significant result. 
  • Eye fixation data showed an average fixation time of 3.72 secs on the gun compared to 2.44 secs on the cheque- statistically significant result 


Participants spent longer looking at the weapon and therefore had more difficulty in picking the suspect from the line up. 

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Making a Case- The Weapon Effect


  • Usefulnes 
  • Reliability 
  • Validity 
  • Strengths and weakness of using a laboratory experiment 
  • Psychology as a science (Validity and Cause and Effect)
  • Ethical issues
  • Sample Bias 
  • Ethnocentrism
  • Ecological Validity 
  • Reductionism
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Making a Case- The Cognitive Interview

The standard interview technique involved 4 stages: 

  • Orientation- The purpose of the interview is stated and the legal requirements are fulfilled such as informing interviewee of their rights. 
  • Listening- The interviewew gives free recall of the events with minimal question 
  • Questions and Answers- The interviewer asks specific questoons based on the previous stage to fill in gaps and reduce ambiguities 
  • Advice- Interviewee is informed of any further step 

This produced unreliable results and was not good at helping witnesses to remember events and valuable evidence was being missed. Memory is an active process and it can be altered by false cues or leading questions. A new interview technique was developed by Psychologists known as The Cognitive Interview. It is designed to be a more effective way of questioning witnesses and it has been shown to produce more reliable recall of events. The technique is rooted within the psychological principle that memory recall is stronger if the context is the same as when the information was learned or if there are cues to recall. 

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Making a Case- The Cognitive Interview

The Cognitive Interview was designed by Fisher and Geiselman and it is based around four component 

  • Report Everything: Encourages witnesses to report all detail no matter how trivial it may be. 
  • Context Reinstatement: tries to recreate the scene of the incident in the mind of the witness, this includes the sights, sounds and smells. They also attempt to model the emotions and feelings of the person at the time. This is based on the concept of cue dependent memory. 

Points One and Two are designed to reinstate context. They get the witness to mentally revisit the scene and mentally reconstruct the incident in their mind. Evidence suggests that we are more likely to recall information if is in a similar context to when it was first experienced or learned, so putting ourselves in a similar state of mind should aid recall. 

  • Recall in reverse order 
  • Recall from a different perspective 
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Making a Case- The Cognitive Interview

Points three and four are based on the idea that once a memory has been stored there is more than one way of getting at it or retrieving it. If one route fails you try another. 

Fisher et al 'Field test of the cognitive interview' 

Aim: To test the cognitive interview in the field 

Participants: 16 detectives from Robbery division Florida, all were experienced with a minimum of five years with the division. 


  • The detectives were divided into twob groups and one group was trained in CI (four one hour sessions was taken to train them)
  • 7 Detectives completed the CI training 
  • Over the next seven months CI trained and non-CI trained detectives recorded their interviews 
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Making a Case- The Cognitive Interview

  • These interviews were analysed by a team at the University of California who were blind to the conditions. 
  • The amount of information gathered by the two groups of detectives was collated. 


  • CI trained detectives elicited 63% more information than the non-CI trained detectives 
  • CI did not take longer to conduct than the standard interview technique 


Cognitive interview technique do work and more information is gathered with no loss of accuracy. The results of this field experiment replicated earlier results from the lab studies. The CI technique does not take longer so it is practical to implement. Adopting CI could help police solve more crimes with minimal effects on time or cost. Significant improvement in the accuracy and amount of information recalled. 

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Making a Case- The Cognitive Interview


  • Usefulness 
  • Strengths and weakness of field experiment 
  • Ecological Validity 
  • Strengths and weakness of qualitative data gathered 
  • Psychology as a science (Validity and can we infer cause and effect)
  • Sample Bias 
  • Ethics 
  • Demand characteristics 
  • Is the study holistic or reductionist 
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Making a Case- Interviewing Suspects

Issues surrounding the whole topic

  • Interviewing is one of the main ways that police gather evidence
  • Conducting interviews is very demanding and the police have to adapt their interviewing styles
  • Criticisms of police interview techniques have been focused on gaining a confession rather gaining facts. This is because they are already convinced of the guilt of the suspect. This assumes the guilt of the suspect which is not in accord with a right that every suspect has which is 'innocent untill proven guilty'
  • Psychological research provides insight into procedures that either help or apprehend the police when they interview suspects. The purpose/primary goal  of an interview is to establish guilt or obtain a confession as this is the most straightforward way to conviction.
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Making a Case- Detecting Lies

It is important that police are able to detect when suspects are lying or when they are telling the truth.A suspect might lie to cover his involvement in a crime or wrongly confess to cover up for another person. It has been known that some family or friends often falsely confess to protect the real perpetrator of the crime.

Police detectives tend to follow the typical body language assumptions such as ‘looking down’ when they try to detect lies. Mann’s study shows the unreliability of assumptions such as eye gaze in assessing whether someone is telling the truth. The study makes suggestions to the factors that are good indicators, such as story cuesgaze, vagueness, movements, contradiction in stories, speech rate and fidgeting. 

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Making a Case- Detecting Lies

Research- Man et al 'Testing Police Officer's ability to detect suspect's lies' 

  • To test police officer's ability to distinguish truth and lies during interviews with suspects 
  • Field experiment, 99 Kent Police Officers (24 female, 75 male, mean age 34.3)
  • Shown 54 video clips, involving 14 suspects of real-life police interviews, each clip backed by further evidence that established truth or lie. 
  • They filled out questionnaires on their experience of detecting liars and they had todecided whether each clip was a lie or truthful
  • Made notes of cues they used to detect the lies 
  • Police officers performed better than chance. 66.2% accurate on lies and 63.6% accurate on truths
  • Most frequently mentioned cues were gaze, movements, vagueness, contradictions in stories and fidgeting. 
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Making a Case- Detecting Lies


  • The study shows that police officers are significantly better at detecting lies than chance.
  • The more experienced an officer is, they better they are at detecting lies.
  • Good lie detectors relied on story cues (more reliable) rather than other factors such as body language. 


  • Usefulness and practical application
  • Ecological Validity/ Method
  • Generalisability/ Sample Bias 
  • Lack of Control Group [Validity]/ Ethics
  • Reliability of Information gained if police are not good at detecting lies 
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Making a Case- Interrogation Techniques

An interrogation is different from an interview because it is accusatory. It ususally takes place after an interview and it is designed to increase arousal and anxiety. An interrogation is useed with uncooperative suspects to attempt to force a confession. The psychology behind interrogation is to create a situation in which the suspect feels that they must admit their guilt. 

The fact that the police officers believe in the suspect's guilt prior to the interrogation is a problem. Often police use coercive methods to gain an admission (which led to some miscarriages of justice) and this has led to the questioning of the quality and validity of the evidence gained at interview. 

The PACE act (1984) requires that all suspect interviews should be recorded and the use of coercive methods during interrogations was reduced. 

Inbau recommends that a non-accusatory interview should always be conducted before an accusatory interrogation. He also argue that an interview rather than an interrogation should be the primary means of determining the truthfulness of a suspect. 

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Making a Case- Interrogation Techniques

Research- Inbau et al 'The Reid 'nine steps' of interrogation 

Inbau felt that it was justifiable for the police to lie, deceive or use tricks to force a confession. These psychological techniques should only be in interrogations with suspects who pre-supposed to be guilty following the initial interview and they are uncooperative. 

1. Direct Confrontation  2. Chance to shift blame 3. Never allow the suspect to deny guilt 

4. Ignore excuses  5. Reinforce sincerity, eye contact, first names 

6. If suspect cries, infer guilt  

7. Pose the 'alternative question', one more socially acceptable, both infer guilt 

8. Get the Suspect to admit guilt in front of witness and 9. Document the admission

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Making a Case- Interrogation Techniques


  • Ethics
  • Usefulness 
  • Reliability 
  • Situational vs Dispositional debate 
  • Should the interrogation technique be used? [False confessions]
  • What does PACE mean for reliability/ validity/ usefulness/ ethics of evidence from suspecsts? 
  • Is PACE a good thing? 
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Making a Case- False Confessions

The pressure of interrogation can lead to false confessions. Sometimes false confessions are a result of psychological deficit such as suffering from mental illness. 

There are different types of false confessions

1. Voluntary [People confess without police coercion] 

2. Coerced Complaint [The suspect knowingly makes a false confession due to a need to escape the stress of the interrogation, or the evidence presented appears to make them look guilt] 

3. Coerced Internalised [The suspect becomes temporarily persuaded that they are guilty. Our memories are fragile and susceptible, young people or people with mental illness particularly]

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Making a Case- False Confessions

Research- Gudjohnsson et al 'A case of false confession' 

  • Document a case of false confession of a youth who was at the time distressed and susceptible to interrogative pressure. 
  • Case study of a 17 year oldaverage intelligence [IQ of 94], suffered from no mental illness [assessed by psychiatrists in prison], personality was within normal parameters 
  • He was accused of two murders [Elderly ladies found battered to death in their homes, their missings gone and also sexually assaulted] 
  • No forensic evidence, he was denied access to a solicitor and interviewed at lengthby the police which led to a confession [14 hours without a break]. During his interview, he was repeatedly accused of lyingThe questions were leading and accusatory [police suggested he was sexually impotent].
  • A year later he was cleared after another man was found guilty. 
  • Scored 10 (high) on Gudjohnsson Suggestibility Scale 
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Making a Case- False Confessions


This is a clear case of 'coerced compliant confession.' 

  • He gave into pressure to escape from the interview situation that he found intolerable 
  • This can happen to anyone, he was normal in terms of intelligence, personality and had no mental illness 
  • However he was highly suggestible


  • Usefulness/ Practical Applications
  • Ecological Validity 
  • Sample/ Generalisability 
  • Reliability 
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Making a Case- Offender Profiling

Offender profiling is about helping the police identify a criminal based on the manner in which the crime was carried out and it does this by providing descriptions of the likely social, physical and mental characteristics of the offender. Offender profiling also helps topredict where, when and how another crime may be committed as in the case of serial killers.

The aim of the whole section is to compare and examine the two approaches to offender profiling. 

Two main ideas/ approaches in Offender Profiling are: 

1. Behavioural evidence- tells us how an offender committed a crime. This links with theTop-down approach. 

2. Criminal Consistency- The idea that a person's behaviour at a crime scene is consistent with their behaviour in other context in real life. This links with the Bottoms-Up Approach

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Making a Case- Top Down Approach

Developed by the FBI in America,the Top-down Approach is a classification system for serious crimes like murder and ****. Murderers are classified as 'organised' or 'disorganised' and this typology is believed to show characteristics of an offender. The typology of the offender is constructed based on how they have committed the crime. 

The steps in profile development: 

1. Data Assimiliation 

2. Crime Classification 

3. Crime reconstruction 

4. Profile Generation 

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Making a Case- Top Down Approach

Research- Ressler, Burgess and Douglas 

They aimed to identify major personality characteristics of serious offenders and how they difffered from non-offenders. Opportunity sample of 36 convicted serial killers and sex murderers in American prisons. 

They conducted lengthy unstructured interview between 1979 and 1983 and information was collected about the crime scenes. 

These information revealed that crimes were either premeditated and planned carefully or more sudden and unrehearsed so there is no effort to hide clues. 

Based on answers to interview questions, participants were divided into organised and disorganised.  24 were categorised as organised and 12 disorganised offenders. 

Conclusion: 1. Crime scene can be used like a fingerprint to identify a murderer 2. Crime scenes reveal evidence of whether offences were by organised or disorganised offenders

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Making a Case- Top Down Approach

Examples of how the Top-down approach works 

An organised murder scene would be planned, with minimal clues which involves hiding the body or moving it from the crime scene or the weapon could be absent. There isaggression before death and the victim is a targeted stranger. Such a murder scene would suggest an organised murderer who is skilledcontrolled, socially competentaverage to high intelligence and employed. 

disorganised murder scene would be spontaneous and the victim is known by the offender. There is little control or restraints and the body is not hidden and other evidence are present. Sexual acts may also be performed before death.Such a murder scene would suggest a disorganised murderer who is unskilleduncontrollablesexually and socially incompetent, less than average IQ and unstable

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Making a Case- Top Down Approach


  • Reliability - assumptions, incomplete data, subjective judgements
  • Validity of methodology 
  • Sample bias 
  • Practical Applications/ Usefulness 
  • Method [Unstructured interviews with serial killers]
  • Narrative and anecdotal evidence 
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Making a Case- Bottom Up Approach

The Bottom-Up approach is data driven and uses statistical analysis. The approach looks for consistencies in offender's behaviour during the crime. Details of the crime scene and information relating to the crime are updated on a computer data base. Statiscal significant matches with previous/ earlier crimes are then sought. This approach works on the basis ofcorrelation between data and it aims to develop a pattern and identify trends. The Bottom-Up approach has a cognitive social aspect to it because it believes that the criminal's behaviour during the crime (indicated through crime scene) is similar to how they are in real life in other social contexts. Canter developed this approach and believes that criminals act consistently and an analysis of their behaviour will reveal a pattern that can offerclues to their general lifestyle, hence it enables the profiler to build a profile. 

Steps in Bottom-Up Approach: 

1. Interpersonal Coherence- Behaviour of the offender during the crime is comparable to how they are in real life. 

    - Targeting (a particular type of victim such as blondes might be significant for the offender)   - Implied Relationship (interactions during attack is significant)

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Making a Case- Bottom Up Approach

2. Significance of place and time (spatial consistency)

  • Place where the crime was commited (home, park, recreational areas), this would give          an indication of whether the offender is a 
  • Marauder: commit crimes close to where they live or feel secure (disorganised                      criminals)
  • Commuters: commit crimes away from where they live (usually organised)

3.Criminal Characteristics 

    - organised or disorganised 

4.Criminal career- has the offender gotten better when he commits crimes?

5.Forensic Awareness- Is the offender aware of forensic process such as not leaving fingerprints? 

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Making a Case- Offender Profiling

Research- Canter and Heritage 'Developments in offender profiling' 

They aimed to identify a behaviour pattern from similarities between offences. 

Content analysis was carried out on 66 sexual assault cases committed by 27 offenders. The data was analysed to Canter's space analysis (which is a multivariate analysis to find correlation/ patterns of behaviour) 

Results showed five variables that were central in all 66 cases: 

1. Vaginal Intercourse 2. No reaction to victim 3. Impersonal language- demeaning to victim 4. Surprise attack 5. Victim's clothing disturbed 

This suggests a pattern of behaviour where the attack is impersonal and sudden and the victim's response is irrelevant to the offender. The identified variables are the most common features of ****, so they are not very usefulf for differentiating between different types of **** crimes. 

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Making a Case- Bottom Up Approach


The five variables have been shown to contribute to all sexual offences but in different patterns for different individuals. 

Analysis of these factors can enable police to decide if an offence has been committed by the same individual. 

Evaluation Points 

  • Usefulness/ Practical Applications
  • Generalisability 
  • Reliability/ Validity 


-Differences and similarities between both approaches to profiling?

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Case Study- Offender Profiling

A cas study of profiling on John Duffy known as The Railway ******. This is an example of how Canter used the Bottom-Up approach to create a profile of John Duffy. He categorised perpetrators as 'marauders' or 'commuters' (commit crimes either near or far away from their home). Duff was found to be a marauder by this criterai. Canter also looked at how the offender related to the victim during the attack and how much dominance was used. In Duffy's case, there was minimal dominance used indicating a weaker individual who was insecure. 

Between 1975 and 1986, 23 women were ***** aged 15 to 32 at railway stations in and around London. 

A list of Canter's preliminary profile: 

  • Marauder: Lives in the area nearby 
  • Residenc: Lives with a wife or girlfriend, no children. 
  • Age: Mid to late twenties, light hair, about 5 feet 9 inches and right handed 
  • Occupation: Semi-skilled, job doesn't bring him in contact with the public and John Duffy was a carpenter who worked at the railway station
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Case Study- Offender Profiling

  • Character: Keeps to himself, has one or two close male friends and has knowledge of the railway systems. 
  • Has previous convictions and considerable sexual experience. 

Canter relied on behavioural characteristics of the perpetrator using the bottom-up approach rather than relying solely on forensic evidence from the crime scene. 

Duffy was laready on the database as he had been interviewed for a domestic offence related crime against his wife. He was one of the 2000 suspects connected to the crime by blood group. When other factors were fed into the database, he was the only one that lived in Kilburn North London, worked on the railways as a carpenter and was the right age.

The witness were unable to identify him out of a pick up earlier due to weapon effect.  

Conclusion: The case of John Duffy illustrates the style of profilling adopted by Canter. It gave hope that the technique woud transform the search for suspects in murder cases. 

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