Techniques of Criminal Investigation IIPertemuan 04

Matakuliah : L0472 - Psikologi ForensikTahun : Feb -2010

Reza Indragiri Amriel

Techniques of Criminal Investigation II

Police Interrogations & Confessions• Would you confess to a crime you did not commit?• 347 students were asked this question:

– Yes – I might confess – 2.6%– No – I would not – 63%– My answer depends – 34%

• Men: 43% Women: 31%

– People usually overestimate their ability to resist to coercion.

Police Interrogations & Confessions• Kassin’s study: 75 subjects • Reaction-time experiment – make sure not to hit the ‘alt’

key or the program will crash. – At first all denied– 50% were accused by a witness

• Given a choice: sign a confession or meet the professor --- all signed the confession

• On their way out meet another confederate who asks what happened: 66% admitted to having crashed the program!

Eyewitness AccuracyResearch on Wrongfully Convicted Defendants

• Wells et al. (1998)– Studied 40 people who were convicted but

later cleared by DNA– In 90% (36) of the cases, there was false

eyewitness identification• Rattner (1988)

– Studied 205 wrongfully convicted defendants– 52% were due to inaccurate eyewitness

testimony• Brandon and Davies (1973)

– Book described 70 cases of people wrongfully convicted due to inaccurate eyewitness testimony

Eyewitness AccuracyAcademic Research

• Buckhout (1975)– Simulated crime on a TV newscast– 2,145 callers– 14.7% were accurate

• Buckhout (1974)– Staged assault on professor in front of 141

students– 7 weeks later, students shown line-up of

six photographs• 40% identified attacker• 36% identified bystander• 23% identified person not there

• Correct Identifications– 20% Buckhout (1980)– 31% Leippe et al. (1978)

Eyewitness Accuracy• Cutler & Penrod (1995)

– unusual behavior by customer

– 2 hours later

• 42% made correct ID• 36% made false ID• 22% could not ID

• Cromag (1996)– Boeing 747 crashed into

an 11-story building in Amsterdam

– TV footage showed rescue attempts after the crash

– 66% of students “remembered” seeing the plane actually hit the building

What do Witnesses Report?Fashsing, Ask, & Granhag (2004)

Attribute % Reporting % Accurate

Gender 99.6 100

Height 91.2 44

Clothing (upper body) 90.8 58

Clothing (head) 89.6 56

Build 84.4 57

Weapon 76.4 71

Clothing (pants) 73.6 53

Age 62.4 38

Type of speech 46.8 84

Factors Leading To Wrongful Conviction(Scheck et al, 2001)

• 81% of time - Mistaken Identification by eyewitnesses • 51% of time - Serology Errors (ABO, protein blood typing) • 50% of time - Police Misconduct • 45% of time - Prosecutorial Misconduct • 35% of time - Forensic Hair Comparison Errors • 34% of time - Junk/Sloppy Science admitted at trial • 32% of time - Bad Lawyering • 22% of time - False Confessions • 20% of time - Deliberately False witness testimony • 19% of time - Deliberately False snitching by informants • 7% of time - Other Forensic Science errors • 1% of time - DNA testing errors

Individual Characteristics Influencing Recollection

• Psychological:IQ, mental retardation, obedience, suggestibility, stress.

• Physiological:Intoxication, withdrawal, sleep deprivation.

Estimator VariablesEstimator Variables (factors over which the justice system exerts little or no

control):

• Age of witness - children and the elderly tend to be less accurate than adults

• Level of confidence - this is not strongly correlated with accuracy of identification

• Facial distinctiveness - faces rated highly attractive or highly unattractive are recognized better than other faces

• Suspect disguise or changed appearance - this leads to less accuracy in identification

• Target salience - it is harder to identify a perpetrator if many people were present at the crime scene

EV (continued)• Exposure duration - it is harder to identify a perpetrator if the

viewing time is short

• Weapon presence - witnesses tend to focus attention on the weapon

• Crime seriousness - people tend to be less accurate in identification tests if the the crime is thought to be less serious

• Stress and arousal - moderate arousal tends to lead to better acquisition of information

• Cross-gender bias - people are more accurate when they identify someone of their own gender

EV (continued)• Cross-racial bias - people are more accurate when they identify someone of

their own race

• Time delay - memory declines over time

• Changes in experiential context - it is sometimes difficult to recognize someone if he or she is seen in a different place

• Post-event information - this can distort a person's memory, and can also be a system variable since this information can come from an interview

System VariablesSystem Variables (factors that are under the control of the justice system):

• Lineup instruction - if a witness expects the perpetrator to be present in the lineup, he or she may feel obligated to pick someone, even if the perpetrator is not there. The witness should be told that the culprit is not present is a legitimate answer

• Foil bias - the suspect should not stand out from the innocent distractors (foils, fillers) in a lineup. The people should wear similar clothing, etc.

SV (continued)

• Investigator bias - the investigator may unintentionally let the witness know which person in the lineup is the suspect

• Presentation bias - a sequential presentation of people in a lineup is better than presenting all people simultaneously

Police Interrogations & Confessions• Most damaging evidence that can be presented in court• Most confessions are negotiated

• Three types of false confessions:– Voluntary: desire for publicity, guilt, psychopathology– Coerced-compliant: avoid further interrogation, gain promised

benefit, avoid threatened punishment– Coerced-internalized: heightened suggestibility

• What percentage of confessions are false? Can’t really know… Cassell (1996): 10-394 annually in the US

Customized Version• compulsive type-attention seeker -- confesses to gain a piece of the fame, impress

others, or to get attention

• compulsive type-homeless -- confesses as a way to get off the streets

• compulsive type-fugitive -- confesses to avoid being prosecuted for a crime elsewhere with stiffer penalties

• compulsive type-guilty conscience -- confesses because believes they are guilty of something

• coerced-compliant type -- Kassin's type who pleads guilty to avoid something aversive in their home environment

• coerced-internalized type -- Kassin's type who comes to believe in their guilt out of interrogation or persuasion

Coerced Internalized Confession“… Quite often we do not succeed in bringing the patient to recollect what has been repressed. Instead of that , if the analysis is conducted correctly, we produce in him an assured conviction of the truth of the construction, which achieves the same therapeutic results as a recaptured memory….… the analyst’s inference can reliably fill up the serious gaps in the patient’s memory.”

(Freud, S.E. 1937, 23:265-266)

Police Interrogations & Confessions

• What can police do :• Misrepresentations of the facts of the case

– Someone has identified the suspect– Someone has confessed already– Staged identification procedure

• Take unfair advantage of emotions, beliefs or medical conditions– If the suspect does not confess, the officer will loose his job, his family will

suffer…– Feigning friendship, concerns– Use of informers in jail– Promising secrecy

• Not inform suspect of potential fact or circumstance that may make the suspect less likely to confess

– Not inform the suspect that an attorney has called– Not inform the suspect of favorable evidence

Police Interrogations & Confessions• What police cannot do:

– Courts are reluctant to restrict interrogation tactics

• Physical and psychological coercion– Physical force and torture

– Threats of harm or punishment

– Isolation and deprivation (food and sleep)

– Promises of leniency

– Most other techniques are left to the Court to evaluate on a case-by-case basis

Interrogation Method• Most pressures are experienced by homicide unit (Drizin

& Leo, 2004)

• The Reid Nine Steps of Interrogation See MSWord supplementary material [Method of Interrogation Reid)]