Title: Steering in the eyewitness identification procedure
1Steering in theeyewitness
identification procedure
- Wendy Alberts
- Jason Duncan
- Brian Wallace
- Prof. Steven Penrod
2Content
- 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
4Eyewitness 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
6Present 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
7Lineup 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).
8Illinois 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.
9However
- 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)
13Possible 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).
14Influence 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.
15Major 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.
16Procedure 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
17Identification 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.
18Identification 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.
19Identification 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
-
21Results
- 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
-
23Results
- 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
24Percentages 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
25Results
- 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.
26Results
- 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)
27Results
- 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) .
28Results
- 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.
29Results
- The fourth hypothesis, that the cautionary
instructions have no effect on the identification
decision of the eyewitness was also confirmed.
30Conclusion
- 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.
31Questions?
- alberts_wendy_at_hotmail.com
- 0(031)6-45092028