Investigation. Part Three: Interrogation

Transcription

1 Investigation Part Three: Interrogation

2 Lie Detection The Polygraph The Relevant-Irrelevant Test The Control Question Test Positive Control Test The Guilty Knowledge Test

3 Weaknesses of the Polygraph Unable to detect in the emotionally nonreactive No guarantee innocent people won t react strongly If you lack faith in the polygraph, you will not respond as expected Guilty will have no fear Innocent will be afraid that polygraph has chance of saying they re lying Lack of standardization (what s a 1 vs. 2) Easy to learn countermeasures Difficult to ascertain accuracy Lying does not necessarily = guilty

4 Accuracy of Polygraph Polygraph detects lying Polygraph detects not lying Polygraph results unclear Suspect is Lying True Positive (78.5%) False Negative (9.7%) Inconclusive (11.8%) Suspect is NOT Lying False Positive (15.5%) True Negative (69.7%) Inconclusive (14.8%)

5 Lie Detection Non-verbal cues Microexpressions Inter-channel discrepancies Eye contact Too much/too little Exaggerated facial expressions Verbal cues Unnecessary details Less specifics and less able to recount things backwards Where s the I and me? More negative emotion words Fewer exclusive words (e.g. except, but, without ) More motion verbs (e.g. walk, go ) Responses to strategic questions Gender differences What about the fmri or voice stress analysis?

6 Interviewing and Interrogation What s the difference? Interview first Interrogation Tactics (40-70% confess) Lying, Evidence Ploys (and the Bait Question) Divide and conquer The Prisoner s Dilemma Highlight inconsistencies Deals Minimization/Maximization Mutt & Jeff/Good Cop-Bad Cop Mr. Big technique The Walk-through (Imagine ) The Reid Technique

7 The Reid Technique 1. The Positive Confrontation 2. Theme Development 3. Handling Denials 4. Overcoming Objections 5. Procuring and Retaining the Suspect's Attention 6. Handling the Suspect's Passive Mood 7. Presenting an Alternative Question 8. Detailing the Offense 9. Elements of Oral and Written Statements

8 False or Coerced Confessions Second leading cause of false convictions FOUR TYPES OF FALSE CONFESSIONS COERCED INSTRUMENTAL End interrogation by acquiescence (coerced-compliant) VOLUNTARY Protect someone else, notoriety AUTHENTIC Becomes convinced of guilt (coercedinternalized) Confessor delusional, mentally ill

9 False or Coerced Confessions Second leading cause of false convictions Who would do that? Fundamental Attribution Error = Confession most compelling evidence to introduce

10 Would you confess? Presenting False Evidence Typing experiment Fast v. Slow Don t hit the ALT key! Computer crashes Confederate: I saw you do it! vs. I don t know what happened. Confession?

11 Confession & Perceptions No Witness Witness Signed Confession Believed Guilt Coerced-compliant Vs. Coerced Internalized

12 Testing a technique: Minimization (+ Deal) In this study, participants were accused of cheating half had and half hadn t on an experiment Participants were then interrogated Minimization: I m sure you didn t know what a big deal it was Deal: We could get this cleared up quickly and you can come back again.

13 Rate of Confessions Control Deal Minimization Min + Deal Guilty Not Guilty

14 False or Coerced Confessions Second leading cause of false convictions (14-32%) Who would do that? Fundamental Attribution Error Certain groups are more susceptible Young Scared Low IQ Mentally ill Those under the influence of substances at time of event Sleep & food deprived As are the Highly suggestible, Eager to Please, and Submissive to Authority

15 If in the situation Situational pressures Extended interrogations Deprivation of food and sleep Use of truth serum Use of leading questions to supply information to the suspect Use of threats or aggression Lying Police under pressure (with few leads) Goal is to obtain confession, not determine innocence Investigator bias Behavioral confirmation Once confession obtained: Evidence Corruption Hypothesis

16 And once presumed guilty The CRIME: Someone took a key that was hidden behind a VCR, used it to enter ROOM 100, and stole $100 from a basket in the cabinet. Guilty expectation (80%) vs. Innocent expectation (20%) Secure a confession Determine guilt vs. innocence Kassin et al., 2003

17 Percentage of Presumed Guilt Innocent Expectation Guilty Expectation Innocent Suspect Guilty Suspect

18 Observer Ratings of Guilt = Behavioral Confirmation Innocent Expectation Guilty Expectation Innocent Suspect Guilty Suspect

19 True or False? Some indicators: How much did interviewer talk vs. suspect? Were there yes AND no responses? Specificity: How specific were the details? Relevancy: Was there more relevant information than irrelevant? Source: Who provided the details? Accuracy: How consistent & correct was the suspect on key details? Verifiability: Were details provided consistent with evidence? Were good questions or bad questions used?

20 Torture? Costanzo et al., 2007 Based on our review, we conclude that psychologists' involvement in designing, assisting with, or participating in interrogations that make use of torture or other forms of cruel, inhumane, or degrading treatment is a violation of fundamental ethical principles, a violation of international and domestic law, and an ineffective means of extracting reliable information. Torture produces severe and lasting trauma as well as other negative consequences for individuals and for the societies that support it.

21 Solutions Video record Using equal-focus camera perspective Time limits Appropriate adult safeguard Expert witnesses