3.4 Profiling + Lie Detection

Question 1

criminal profiling definition

Answer 1

• 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

Question 2

early attempts at criminal profiling

Answer 2

• 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

Question 3

deductive criminal profiling

Answer 3

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)

Question 4

inductive criminal profiling

Answer 4

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

Question 5

FBI approach: organised + disorganised

Answer 5

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

Question 6

FBI problems

Answer 6

• little research to examine, what has been done has raised doubts
• can’t account for offenders displaying mix of both features

Question 7

statistical approach

Answer 7

• 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

Question 8

geographic profiling

Answer 8

• 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

Question 9

how accurate are criminal profiles?

Answer 9

• 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

Question 10

accuracy: experimental evaluations

Answer 10

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

Question 11

3 ways to catch a liar

Answer 11

• examine physiological response
• observe nonverbal behaviour
• analyse content of what they say

Question 12

polygraph history

Answer 12

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

Question 13

polygraph

Answer 13

• 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

Question 14

polygraph use around the world

Answer 14

• 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

Question 15

relevant/irrelevat test

Answer 15

• 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

Question 16

Control Question Test (CQT)

Answer 16

• 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

Question 17

CQT process: irrelevant questions

Answer 17

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

Question 18

CQT process: control q’s

Answer 18

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

Question 19

CQT process: relevant

Answer 19

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

Question 20

CQT phase 2

Answer 20

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

Question 21

CQT phase 3

Answer 21

control, relevant, and irrelevant questions asked several times over

Question 22

CQT phase 4

Answer 22

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

Question 23

criticisms of CQT

Answer 23

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?

Question 24

Guilty Knowledge Test (GKT)

Answer 24

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

Question 25

what precautions should be taken for GKT?

Answer 25

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

Question 26

GKT problems

Answer 26

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

Question 27

how accurate are polygraph tests?

Answer 27

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

Question 28

expert opinions on methods

Answer 28

• 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

Question 29

current directions: voice stress analysis

Answer 29

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

Question 30

current directions: brain-based lie detection

Answer 30

• 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