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Steering in the eyewitness identification procedure

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Title: Steering in the eyewitness identification procedure


1
Steering in theeyewitness


identification procedure
  • Wendy Alberts
  • Jason Duncan
  • Brian Wallace
  • Prof. Steven Penrod

2
Content
  • Example
  • Eyewitness misidentification
  • Present study
  • Illinois study
  • Major hypotheses
  • Procedure and design
  • Results
  • Conclusion

3
  • 17 year old Ruben Cantu was convicted of murder
    and executed in 1993 . The prosecutor accused
    him of shooting his victim nine times. Now it is
    thought that he was likely innocent. The only
    eyewitness in this case was shown the picture of
    Ruben Cantu three times at which point he
    recognised Cantu. He has recanted and after the
    execution, a 15 year old accomplice testified
    that Ruben Cantu was never there.
  • Source http//www.ad.nl/buitenland/article65986.e
    ce

4
Eyewitness Misidentifications
  • In June 2008, the Cardozo Law School Innocence
    Projects web site reports that 217 individuals
    convicted of crimes have been exonerated with DNA
    testing since 1992 (www.innocenceproject.org).
  • 75 eyewitness misidentifications
  • Most crimes do not include DNA-rich biological
    traces.

5
  • Wells (1978) argues that two types of variables
    can be distinguished in eyewitness research
  • (a) estimator variables and
  • (b) system variables

6
Present Study
  • The influence police officers can have on the
    eyewitness in the lineup procedure
  • lineup presentation
  • the presence of the perpetrator in the lineup
  • giving cautionary instructions before the lineup
    procedure begins

7
Lineup presentation
  • Simultaneous display of six photographs
  • Sequential lineup in which the photos of the
    suspect and foils are displayed one at a time
    (Wogalter et al., 2004).
  • Sequential procedure reduces the number of false
    identifications with no loss in the number of
    accurate identifications
  • (Lindsay Wells, 1985 Cutler Penrod, 1988
    Lindsay et al., 1991 Keller et al., 2001
    Steblay Dysart, 2008).

8
Illinois Study (Mecklenburg, 2006)
  • No field studies until 2006
  • First field study comparing the simultaneous
    line-ups and sequential line-ups
  • First field study to examine both photo arrays
    and live line-ups.

9
However
  • Confounds blindness and procedure in its design
  • Lower overall rate of false identifications in
    the single-blind simultaneous condition than
    predicted by the research experiments
  • police officers may not have been reporting foil
    identifications when they knew those
    identifications were erroneous or steered the
    eyewitness to the identification of the suspect

10
-- suspectsmix of guilty and innocent unclear --
9-person arrays -- nearly 1/3??? of IDs are
clearly bad guesses of foils
11
  • 6-person arrays
  • About 1 in 4 IDs is a clear error

12
(No Transcript)
13
Possible reasons for the discrepancy are buried
in the Illinois report ?The low number of
filler IDs emerged from a non-blind simultaneous
procedure in which it appears that the police
could ignore IDs that did not meet their
"Probable cause" standards (Appendix, pp. iii-iv)
?This practice seems akin to the Queens practice
in which "an identification was recorded only
if it was based upon a high level of confidence,
so that all tentative identifications were
recorded as "no identification." (p. 43).
14
Influence of lineup-administrator
  • Haw Fisher ( 2004) witnesses are more likely
    to make decisions consistent with the lineup
    administrators expectation when the level of
    contact between the administrator and the witness
    is high rather than low
  • Garrioch and Brimacombe (2001) the confidence of
    the eyewitness rises when the witness chooses the
    lineup member who their lineup administrator
    thinks is guilty.

15
Major Hypotheses
  • 1. Police-officers can influence eyewitnesses to
    select a suspect and avoid foil identifications.
  • 2. Police-officers can do this without the
    eyewitnesses realizing they are being led to the
    suspect or avoiding foils.
  • 3. Police-officers can influence eyewitnesses in
    a non-blind simultaneous procedure more than in a
    non-blind sequential procedure.
  • 4. Cautionary instructions have no effect on the
    identification decision of the eyewitness.

16
Procedure and Design (2x3x2x2)
  • 240 Participants (eighteen years or older)
  • Two videos, one distracter video and one of a
    staged indoor theft
  • Twenty minutes filler task

17
Identification procedure
  • Cautionary instructions
  • The suspect may not be in the lineup, you
    dont need to make a choice and you should not
    assume that the administrator knows who the
    suspect is.
  • Lineup where the thief was present or a lineup
    with a substitute for the thief (innocent
    suspect).
  • Match to description procedure.
  • innocent suspect a foil who looked very
    similar to the perpetrator.

18
Identification procedure (2)
  • The line-up was administered either
  • - simultaneous
  • - sequential show-the-pictures-twice (S2)
  • - sequential-with-stopping-rule (SS)
  • sequential procedure stack was back loaded to
    twelve cards (six blank cards), so the
    participants did not knew that the stack
    contained only six photographs.

19
Identification procedure (3)
  • An administrator who was trying to steer them to
    choose the (innocent) suspect/away from a foil or
    a blind condition
  • Steering The administrator signalled in the
    direction of the suspect with non-obvious,
    non-verbal cues and made comments like good and
    that is helpful and gave no reinforcements for
    the foils.
  • Blind screen between the administrator and the
    participant, so that the administrator couldnt
    see the lineup and couldnt influence the
    participant. Lineup was also randomised.

20
  • Percentages of choices participants made in the
    Target Absent (TA) condition as a function of
    lineup procedure


  • Lineup Procedure

  • TA Lineup decision N SS() N S2
    () N Sim()
  • False Identification 5 11.9 10 25.0
    10 26.3
  • all n.s.
  • Correct Rejection 33 78.6
    19 47.5 8 21.1
  • SS-S2 SS-SM S2-SM
  • Foil Identification 4 9.5 11
    27.5 20 52.5
  • SS-S2 SS-SM S2-SM
  • Total (N120) 42 100.0 40
    100.0 38 100.0
  • plt.05 SS Sequential-with stopping-rule
    procedure
  • plt.01 S2 Sequential-show-the-photos-again
    procedure
  • Sim Simultaneous procedure

21
Results
  • First, procedure mattered
  • - Results show superiority of the sequential
    lineup procedure when it is properly conducted

22
  • Table 2 Percentages of choices participants made
    in the Target Present (TP) condition as a
    function of lineup procedure


  • Lineup Procedure

  • TP Lineup decision N SS() N S2 () N
    Sim()
  • Hit 8 20.5 18 42.9 19
    48.7
  • SS-S2 SS-SM S2-SM
  • Lineup Rejection 23 59.00 11
    26.2 7 17.9 SS-S2 SS-SM
    S2-SM
  • Foil Identification 8 20.5
    13 31.0 13 33.3
  • all n.s.
  • Total (N120) 39 100.0 42
    100.0 39 100.0 
  • plt.05 SS Sequential-with stopping-rule
    procedure
  • plt.01 S2 Sequential-show-the-photos-again
    procedure
  • Sim Simultaneous procedure

23
Results
  • The first hypothesis, that police officers can
    influence eyewitnesses to select a suspect and
    avoid foil identifications was confirmed.
  • steering administrator more suspect
    identifications.
  • They could be steered in every procedure

24
Percentages of choices in the Target Absent (TA)
and the Target Present (TP) condition, as a
function of administrator steering
  • Administrator
  • Steering Blind
  • Lineup and decision N () N ()
  • Target Absent lineup
  • False Identification 19 31.7 6 10.0
  • Correct Rejection 28 46.7 32 53.3
  • Foil Identification 13 21.7 22 36.7
  • Total (N120) 60 100.0 60 100.0
  •  
  • Target Present Lineup
  • Hit 34 56.7 11 18.3
  • Rejection Lineup 16 26.7 25 41.7
  • Foil Identification 10 16.7 24 40.0
  • Total (N120) 60 100.0 60 100.0

25
Results
  • The second hypothesis, that police officers can
    influence eyewitnesses to select a suspect and
    avoid foil identifications without the
    eyewitnesses realizing they were being led was
    not entirely confirmed.
  • Witnesses in the steering condition mentioned
    things the administrator did or said that
    influenced their decision more than witnesses in
    the blind condition (?230.84, plt.01).
  • Witnesses also indicated that the administrator
    influenced their decision significantly more when
    the administrator was steering than when he was
    blind t(233)2.171, plt.01.

26
Results
  • Influence of the administrator on their
    decision
  • - steering (M2.73) vs. blind (M2.10).
  • low end of a 9-point scale
  • Witnesses thought lineup photos and their memory
    were much more influential than the
    administrator
  • -photos steering (M4.98) vs photos blind
    (M5.77) (sg)
  • -memory steering (M7.32) vs memory blind
    (M7.25)

27
Results
  • The third hypotheses, that police officers can
    influence eyewitnesses to select a suspect in a
    non-blind simultaneous procedure more than in a
    non-blind correct conducted sequential procedure
    (SS) was confirmed.
  • Simultaneous procedure (55.3) vs SStop procedure
    (26.8) .

28
Results
  • No significant difference was found between
    witnesses with a S2 procedure (51.2) and the
    simultaneous procedure (55.3) when they were in
    the steering condition.
  • That is, when the sequential procedure was not
    conducted properly (showing them the pictures
    twice), it was as easy to steer the witness to
    the (innocent) suspect as in the simultaneous
    procedure.

29
Results
  • The fourth hypothesis, that the cautionary
    instructions have no effect on the identification
    decision of the eyewitness was also confirmed.

30
Conclusion
  • If we compare the results of the present study
    with those of Illinois and Queens, we see that
    the steering administrator is a plausible
    explanation for the substantially lower overall
    rate of false identifications in the non-blind
    simultaneous conditions used in those studies.
  • In the present study the witnesses made fewer
    foil identifications in the steering condition
    than the blind condition and did so without
    dramatically triggering witness suspicions.

31
Questions?
  • alberts_wendy_at_hotmail.com
  • 0(031)6-45092028
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