3.4 Profiling + Lie Detection Flashcards

1
Q

criminal profiling definition

A
  • technique for identifying major personality + behavioural characteristics of individual based on analysis of crimes he/she has committed
  • includes info about demographics, personality, behaviour
  • used in range of contexts, commonly SERIAL homicide + rape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

early attempts at criminal profiling

A
  • late 1400s - catholic church wrote one up for eradicating witches
  • 1888 - surgeon attempted to profile jack the ripper, no success
  • 1956 - Dr James Brussel Mas Bomber
    FBI + beyond:
  • 1970s - development criminal profilinf program at FBI
  • today: international programs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

deductive criminal profiling

A

profiling the background characteristics of an unknown offender based on EVIDENCE BY INDIVIDUAL left at crime scene
* relies on logical reasoning (which can sometimes be faulty)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

inductive criminal profiling

A

profiling background characteristics of offender BASED ON WHAT WE KNOW ABOUT OTHER SOLVED CASES
* relies on determination of how likely offender will possess certain background characteristics given prevalence of characteristics among known offenders who’ve committed similar crimes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

FBI approach: organised + disorganised

A

organised: planned, targeted, controlled conversation, restraint, body moved + hidden, evidence removed
- perpetrator: intelligent, socially + sexually competent, lives w/ partner, follows crime details in news
disorganised: spontaneous, depersonalise, chaotic scene, sudden violence, no restraint, body + evidence left
- perpetrator: avg Q, sexually incompetent, live alone, near crime scene, little interest in media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

FBI problems

A
  • little research to examine, what has been done has raised doubts
  • can’t account for offenders displaying mix of both features
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

statistical approach

A
  • data collected from solved crimes + analysed using complex stats
  • idea; groups of actions tend to occur together revealing a typology - USUALLY PRETTY GOOD
  • only as good as inputted data, unstable if small sample size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

geographic profiling

A
  • analysis of crime scene locations to determine most probable area of offender residence
  • assumes offenders don’t travel long distances from home to commit majority of crimes
  • can be QUITE ACCURATE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how accurate are criminal profiles?

A
  • benefits: greater understanding of case, reinforce judgements about offender
  • only 2.6% respondents indicated profiles led to direct identification of offender
  • profiles often contain ambiguous advice, 24% of opinions considered ambiguous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

accuracy: experimental evaluations

A

pinizzotto et al 1990
- gave solved cases (1 murder 1 sex offence) to profilers, detectives, psychologists, students
- profilers did better with sex offense, not murder
- profilers didn’t use info any differently to other groups
kocsis et al 2000
- psychologists slightly better than police + psychics
- some evidence profilers were better than psychologists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 ways to catch a liar

A
  • examine physiological response
  • observe nonverbal behaviour
  • analyse content of what they say
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

polygraph history

A

19th century put forward by lombroso
* early 20th century, polygraph machine first used
- 1917 william marston claimed todetect oying by measuring systolic blood pressure
- 1932 john a larson built forerunner of modern polygraph measuring pulse rate, blood pressure, respiratory changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

polygraph

A
  • measure physiological change, not lies (lying is operationalised AS increased blood pressure, heart rate, respiration, sweating)
  • uses: criminal investigaitons, verify a crime has occurred, pre-employment screening for security agencies + police
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

polygraph use around the world

A
  • used to be quite common i US, now mostly for investigative purposes (not admissible in court)
  • Aus, UK, most europe not used as legal process, security services still use sometimes
    polygraph prohibited from use in criminal investigations in NSW from 1983
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

relevant/irrelevat test

A
  • akss quesions relevant and irrelevatn to crime (wow)
  • idea; guilty people will respond more strongly when lying about relevant questions
  • BUT innovent person will know which are relevant and will worry about their responses to them, would lead to many false positive errors
  • no longer used in law, sometimes in employment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Control Question Test (CQT)

A
  • designed to overcome problems w/ relevant/irrelevant q test
    1. CQT begins w/ pre-test interview
  • yes/no questions formulated and discussed with suspect. irrelevant questions should prompt no arousal. relevant questions
  • control questions: related to case, but not crime itself - vague, will embarrass both innocent and guilty. q’s require honest yes but suspect is told they must lie and that the polygraph will detect this fact
17
Q

CQT process: irrelevant questions

A
  • used to obtain baseline e.g. are you left-handed
18
Q

CQT process: control q’s

A

deal with prior behaviour. designed to provoke anxiety. before age 25, did you ever verbally threaten to hurt anyone

19
Q

CQT process: relevant

A

deal with the crime. did you assault sam smith the evening of november 11th?

20
Q

CQT phase 2

A

stimulation test - convince suspect that polygraph will be able to detect lies (often involves card trick)
- designed to make guilty more fearful and the innocent less fearful

21
Q

CQT phase 3

A

control, relevant, and irrelevant questions asked several times over

22
Q

CQT phase 4

A

score using either global approach (subjective impression) or numerical scoring approach:
if relevant > control = negative score
if control > relevant = positive score
* all comparisons summed to give total score (often +5 = truth, -5 = deceptive. in-between = inconclusive)
- sometimes 5th phase added: tell suspect result in hope will confess

23
Q

criticisms of CQT

A

BASICALLY: based on lots of assumptions that might be wrong
- control question formulation difficult
- scoring not sufficiently quantified –. subjective = discretion of interviewer
- ethics - deceiving suspect as to how polygraph works
- don’t know if subject actually believes stim test
- why would innocent show stronger response to control than relevant questions
- why would guilty show stronger response to relevant than control?

24
Q

Guilty Knowledge Test (GKT)

A

concealed/guilty knowledge test assesses if suspect has information that only criminal would know
* asks suspect multiple choice questions, one option is correct
* assumes if suspect guilty will react strongly to correct information
* innocent would not recognise crime-relevant details, so would not respond

25
Q

what precautions should be taken for GKT?

A
  • examiner shouldn’t know correct answer (DOUBLE BLIND)
  • check alternatives are equally arousing for innocent person
26
Q

GKT problems

A

applicability: cannot be used unless lots of details are known only to perpetrator
knowledge of perpetrator: assumes perpetrator knew/remembered details - may not be true

27
Q

how accurate are polygraph tests?

A

CQT
* majority guilty suspects correctly identified (84% - 92% guilty correct)
* large false positives (9% - 24%)
GKT
* very good at identifying innocent participants (95%)
* less accurate at guilty participants (false negatives) (85%)
- BETTER to have false negatives

28
Q

expert opinions on methods

A
  • most think GKT based on scientifically sound theory
  • most would conclude that someone who fails 8/10 GKT has guilty knowledge
  • 99% agree that CQT can be beaten by increased response to control questions
29
Q

current directions: voice stress analysis

A
  • VSA: advocates suggest lying more stressful, changes your voice
  • most research found results no greater than chance at able to distinguish lying + truth
30
Q

current directions: brain-based lie detection

A
  • recent research: EEG + brain scanning investigated by functional magnetic resonance imaging fMRI
  • generated a lot of interest, but results not shown sufficient consistency to be admissible in court