Forensics (need to complete L6) Flashcards
Forensic Psychology
Application of psychological knowledge and theories to all aspect of the criminal and civil justice system
History of Forensic Psychology
- James Cattell (1895) - recall things they witnessed in their everyday life
- Afred Binet (1900) invented the intelligence test
- Varendonck (1911) was called to be an expert witness: 84% of children’s said a colour when the teacher didn’t have a beard, hence inaccurate
- Eyewitness Research: People were not accurate
Functions of an Expert Witness (important)
- Aid in understanding a particular issue relevant to the case
- Allowed to express their opinion
Challenges of Providing Expert Witness
- Lack ecological validity
- Psychologist may become advocates and lose their objectivity
Admissibility Criteria
- Experts must satisfy judge
- Experts have special knowledge above and beyond that of average juror
- R vs Turner 1975: Just because experts are well qualified does not mean they are helpful to the jury
Expert Evidence
- Fingerprints
- Facial Mapping
- Hair analysis
Estimator Variables
- Variables that are present at the time of the crime and cannot be changed
- E.G. lighting at the event, characteristics of witness
Estimator Variables: FLASHBULB MEMORY
- When we experience a traumatic experience, we have a vivid memory
- But memory degrades overtime. E.G. Holocaust survivors who have vivid memories make mistakes in their perpetrators
Estimator Variables: YERKES-DODSON LAW
- Emotional Levels
- Memory best at optimum level of arousal
Easterbrook Hypothesis
- Strong memorise for central details
- Poor memory for peripheral details
- E.G. more alert after hearing a gunshot
System Variables
- Variables that can be manipulated afterwards and impact the accuracy of witnesses
- E.G. The way police question a witness
Misinformation Effect/False Memory
Exposure to incorrect information about an event after it has occurred often causes people to incorporate this misinformation into their memories
- Loftus
- Loftus and Palmer
Loftus and Pickrell (1995)
- Gave participants narratives of being “Lost for an extended time in a shopping mall at age 6 and rescued by an elderly person”
- 25% reported being lost in a mall and gave rich and vivid details
Wade et al (2002)
- Participants were shown a fake print advertisement that described a visit to Disneyland and how they met and shook hands with Bugs Bunny.
- Later, 16% reported meeting and shaking hands with Bugs Bunny
Williams (1994)
- Interviewed 129 women how bad childhood sexual abuse
- 38% of the women did not report any abuse
Implications of Misinformation Effect
Ask open and non-leading questions
Factors increasing susceptibility to the misinformation effect
- Age
- Hypnosis
- Detail is peripheral
Target-Present Lineups
- Lineup contains culprit
- To correctly identify culprit to prove guilty
Target-Absent Lineups
- Lineup does not contain culprit
- To correctly reject all lineup members to prove suspect innocence
How do we know ID evidence is inaccurate
- Surveyed Justice Officials
- DNA Exoneration Cases
- Empirical studies of ID performance
- Surveyed Justice Officials
Over 70% thought that erroneous convictions occurred in less than 1% of the cases
- DNA Exoneration Cases
- Link a person to a crime with a high degree of certainty
- In 2015, 72% of DNA exoneration were due to mistaken identification
- Empirical studies of ID performance
a. Field Studies: high in ecological validity but lack experimental control
b. Laboratory Studies: allow more control but lack ecological validity
Piggott et al., (1990)
- Confederates go into banks and perform an unusual transaction
- Bank teller’s falsely identified 35.8% of IDs
Wells, (1993)
- Participants watch staged crime and required to identify the perpetrator lineup
- False ID varied from about 0% to about 100%
Factors Affecting Estimator Variables
- Viewing conditions
- Fatigue
- Own race bias
Factors Affecting System Variables
- ID procedures
- Composition of lineup
- Instructions given to witnesses
Identification Procedures
- Showups
- Lineups
Identification Procedures: SHOWUPS
- One person lineup containing only the suspect
- Only acceptable if not enough evidence to arrest and conduct lineup
Identification Procedures: LINEUPS
- Ability of the witness to identify the suspect when seen with several foils
Composition of ID Procedure
- Lineup should consist of foils who look like the eyewitness’s description
Format of ID Procedure
- Photo-lineups
- Mugshot Searches: witness sees a face in a mugshot search is likely to pick that person out in a lineup, even if not the culprit due to unconscious transference
Unconscious Transference
- When people remember a face, but mistake the circumstances in which they saw the face
- E.G. Robert Clark
Instructions Given
- Witness should be told that suspect may or may not be in the lineup
- E.G. Police officer officer who knows suspect might unintentionally looking carefully at a particular suspect and witness notices
Lineup Presentation
- Simultaneous Lineup
- Sequential Lineup
- Lineup Presentation: SIMULTANEOUS LINEUP
All lineup members are presented at the same time
- Lineup Presentation: SEQUENTIAL LINEUP
Members are presented one at a time and must decided if is or is not the criminal before seeing another photo
- a. Sequential Lineup: RELATIVE JUDGEMENT
- Comparing lineup members to other lineup members
- b. Sequential Lineup: ABSOLUTE JUDGEMENT
- Comparing lineup members to witness’ memory
Simultaneous vs Sequential
- Sequential lineups were less likely to identify guilty or not guilty
- When a suspect was identified, they were more likely to be guilty when using sequential
Robbery-Murder Case
- Circumstantial Evidence
- Circumstantial Evidence + eyewitness testimony
- Circumstantial evidence + discredited eyewitness
Improve ID procedures
- Educate jurors
- Conduct a thorough pre-lineup interview of the eyewitness
- Decide when or even whether to conduct a lineup
- Use a neutral administrator to conduct the lineup
- Select lineup fillers so that the suspect does not stand out
- Give non suggestive pre-lineup instructions to eyewitnesses
- Take a confidence statement from an eyewitness immediately upon an identification decision rather than later
- Video-record the entire procedure
- Avoid repeated identification procedures with the same witness and suspect
- Avoid “showups” (an identification procedure with a single suspect) in favour of lineups when possible
Profiling
- Identifying the major personality of an individual
- Analysis of the crimes he/she has committed
History of Profiling
- Late 1400s - Text was written by contractors to the Catholic Church
- 1888 - Police surgeon attempted to profile ‘Jack the Ripper’
- 1956 - Dr James Burssel’s profiled ‘Mad Bomber’
- 1970 - Development of criminal profiling program at FBI
Methods of Profiling
- Deductive Criminal Profiling
- Inductive Criminal Profiling
- Methods of Profiling: DEDUCTIVE CRIMINAL PROFILING
Based on evidence left at the crime scene
- Methods of Profiling: INDUCTIVE CRIMINAL PROFILING
Based on what we known about other solved cases
Inductive Criminal Profiling
- FBI Approach
- Statistical Approach
- Geographic Profiling
Inductive Criminal Profiling: FBI APPROACH
- Organised
- Disorganised
Inductive Criminal Profiling: STATISTICAL APPROACH
- Data collected from solved crime
- Analysed using complex statistics
Inductive Criminal Profiling: GEOGRAPHIC PROFILING
- Analysis of crime scene locations to determine most probable area of offender residence
- Hence, buffer zone
Accuracy of Profilers
82.6% of police officers find them useful
Pinizzotto et al (1990)
Profilers did better when given solved sex offense then solved murder case
Kocsis et al. (2000)
Psychologists were slightly better than police and psychics with solved murder cases
Deception
Deliberate attempt to create another belief which is untrue
Polygraph
- Measures phsyiological change
- Does not detect lies
Types of Polygraph Tests
- Relevant/Irrelevant Test
- Control Question Test (CQT)
- Guilty Knowledge Test (GKT)
- Types of Polygraph Tests: RELEVANT/IRRELEVANT TEST
- Ask questions relevant and irrelevant to the crime
- Innocent person will know which are the relevant questions and will worry about their response to them
- Leading to false positive errors
Irrelevant Questions
- Establish a baseline for normal levels
Relevant Questions
- Questions that deal with the crime
- Types of Polygraph Tests: CONTROL QUESTION TEST (CQT)
- Overcomes relevant/irrelevant test by including control question
Control Questions
- Establish a baseline for physiological levels to compare with the responses to relevant questions
Control Question Test: PHASE 2
- Stimulation Test: Convince suspect that the polygraph will be able to detect lies
Control Question Test: PHASE 3
- Repeat control, irrelevant and relevant questions several times over
Control Question Test: PHASE 4
Scored using either:
- Global Approach: subjective impression
- Numerical Approach:
- Relevant > Control = negative scoreif
- Control > Relevant = positive score
Criticisms of CQT
- Formulation control questions is difficult
- Strong element of deception
- Types of Polygraph Tests: GUILTY KNOWLEDGE TEST (GKT)
- Assume if the suspect is guilty they will react strongly to correct information
- Present information in multiple choice answer
Criticisms of GKT
Cannot be used unless lots of details are known only to the perpetrator
Accuracy of Polygraph Test
CQT
- Majority of guilty suspects correctly identified
- Large number of innocent suspects falsely
identified
GKT
- Very accurate at identifying innocent participants
- Less accurate at identifying guilty participants
Current Directions in Lie Detection
- Voice Stress Analysis
- Brain Based Lie Detection
Criminal Interrogations and Confessions
- Positive Confrontation
- Theme Development
- Handling Denials
- Overcoming Objections
- Retaining Suspect’s Attention
- Handling the Suspect’s Mood
- Creating an Oppurtunity to Confess
- Oral Confession
- Converting Oral Confession to Written Confession
- Positive Confrontation
Present real or fictional evidence
- Theme Development
If suspect is emotional, then minimisation
- False sense of security
- “Anyone in the same situation would have done that”
If suspect is non-emotional, then maximisation
- Exaggerate seriousness of the crime
- Exaggerate magnitude of the charges
- Handling Denials
- Stopping the suspect’s repetition of denials
- The more frequently a suspect repeats a lie, the harder suspect to tell truth
- Overcoming Objections
Make them feel that their objections are ineffective
- Retaining Suspect’s Attention
- Moving physically closer to subject
- Maintaing eye contact
- Handling the Suspect’s Mood
- Focus on the suspect’s mind on possible reasons for committing the crime
- Creating an Opportunity to Confess
- Suspects are given an opportunity to provide an excuse for the crime
- E.G. “Was this your idea or did someone talk you into it’”
- Oral Confession
- Ask them brief clear questions and receive brief clear response
- Converting Oral Confession to Written Confession
Criticisms of 9-Step Approach
- The more you pressure to do something, the more resistant they become
- Officers have confirmation bias since they already believe the suspect is guilty
- Deception is unethical
- Guilty suspect may catch on to bluffing and not believe anything told
- False confessions
False Confessions
- Confess a crime they did not commit
- Exaggerate their involvement in a crime they did commit
- 27% of prisoners had given false confessions
Types of False Confessions
- Voluntary
- Coerced-Compliant
- Coerced-Internalised
- Types of False Confessions: VOLUNTARY
- Occurs without being prompted by the police
- Types of False Confessions: COERCED-COMPLIANT
- Occurs in desire to escape further interrogation, gain a promised reward or avoid threatened punishment
- Types of False Confessions: COERCED-INTERNALISED
- Highly suggestive interrogations
- Confessor “believe” that they committed the crime
False Confessions in Laboratory
PEACE Model
- Planning and Preparation
- Engage and Explain
- Account
- Closure
- Evaluation
Current Practices
All interviews recorded with Electronic Recording of Interviews with Suspects (ERISP)
Jury
Apply the law to the evidence and render guilt or innocence
Jury Selection
Choosing and shaping jury through the use of:
- Preemptory Challenges
- Challenge for Cause
- Jury Selection: PREEMPTORY CHALLENGES
Removal of a limited number of prospective jurors without specifying reasons
- Jury Selection: CHALLENGE FOR CAUSE
Both parties also have an unlimited right to challenge with “cause
Studying Jury Behaviour
- Post Trial Interview
- Archival Records
- Simulation Techniques
- Field Studies
- Studying Jury Behaviour: POST TRIAL INTERVIEW
Not possible in many countries because jurors are forbidden by law
- Studying Jury Behaviour: ARCHIVAL RECORDS
- Transcipts
- Police interviews
- Studying Jury Behaviour: SIMULATION TECHNIQUE
- Mock jurors are presented with a simulated trial
- Questionable generalisability to real life cases
- Studying Jury Behaviour: FIELD STUDIES
- Research conducted within a real trial
- Observe the process as it is occurring
- High ecological validity
Researching a Verdict
- Listening to the evidence
- Disregarding inadmissible evidence
- Judge’s instructions
- Juror decision-making
- Deliberations
- The final verdict
Demographics