A larger sample of police files was reviewed
in 2001 for 689 California identification attempts
following crimes ranging from homicide to theft.
Similar rates of SI were found for 284 simultaneous
photo lineups (48% SI) and 58 live simultaneous line-
ups (50% SI). Live lineup decisions produced 24%
false alarms and 26% lineup rejections. (Researchers
do not always separate filler and “no choice” deci-
sions, often because police reports do not provide this
level of detail.) Showup identification rates were sim-
ilar whether live (258) or photo (18)—76% and 83%
SI, respectively—and significantly higher than rates
for the full array. Of particular interest were 66 lineup
identifications by eyewitnesses who had made an ear-
lier identification of the same suspect. Significantly
more SIs were made in later attempts (62%) compared
with witnesses attempting a single identification
(45%). A 2005 update of the California simultaneous
lineup data, including overlap with the earlier data set,
produced an SI rate of 52% for photo and 46% for live
lineups; filler picks were at 15% for the overall group.
Additional archival summaries come from
researchers in England. These include 2,200 witness
identifications for 930 live, simultaneous identity
parades. Outcome similarities across studies are evi-
dent (also including an unpublished third study of 843
witnesses and 302 lineups by the London police):
When the offender was not known previously to the
witness, approximately 40% of witnesses identified
the suspect, 20% chose a filler, and 40% made no
choice from the lineup. When the perpetrator was pre-
viously known, not surprisingly, SI was more likely.
Along with recent reforms in lineup practice, data
are emerging that capture eyewitness responses under
double-blind sequential lineup practice—a one-at-a-
time presentation of lineup members, administered by
an investigator who does not know the identity of the
suspect. A 2006 Minnesota pilot project generated SI
rates of 54%, fillers 8%, and “no choice” 38%. This
field study also showed that repeated viewing of a
lineup by the witness was associated with a reduction
in SIs and rising filler selections.
Some of these descriptive studies have also
attempted to examine the impact on witness decisions
of crime-incident features, such as weapon presence.
The researchers are careful to point out the dangers
of comparing pseudo-experimental conditions. For
example, weapon absence may be confounded with
crime type (fraud vs. robbery) and, therefore, also
with differential witness attention, quality of culpritdescription, and delay prior to lineup. While substan-
tial support has been found in controlled laboratory
tests for the negative impact of factors such as weapon
presence, delay, and cross-race identification, field
studies present inconsistent results. The difficulty of
interpreting study results following nonrandom assign-
ment is illustrated by a London research team, com-
paring a “lineup suite” with a standard police-station
setting. The researchers noted that lineups assigned
to the suite differed in important ways from those
assigned to ordinary police stations: time lapsed since
the crime event, race of the suspect, and crime vio-
lence. Lineup setting was confounded with other criti-
cal factors.
Finally, an ancillary line of hybrid lab-field research
has developed around testing for fairness of real line-
ups. A mock witness procedurerequires lab partici-
pants, who have not seen the crime and are armed
only with the culprit description provided by the real
witness, to identify the suspect from the lineup. This
procedure is typically used to evaluate individual line-
ups suspected of biased structure. An emerging use of
this paradigm is to analyze a sample of lineups from a
jurisdiction of interest. Lineup fairness was tested in
England using this procedure, demonstrating video
lineups to be fairer than photos. In the Minnesota pilot
of double-blind sequential lineups, a mock witness
procedure confirmed fair lineup construction through
a sample of field lineups.
As we look to the future, there is great potential for
information gain in well-designed experimental field
tests that include methodological necessities such as
random assignment and double-blind administration,
but data from such tests are not yet available.Nancy K. SteblaySee also Estimator and System Variables in Eyewitness
Identification; Eyewitness Memory; Showups;
Simultaneous and Sequential Lineup PresentationFurther Readings
Klobuchar, A., Steblay, N., & Caligiuri, H. (2006). Improving
eyewitness identifications: Hennepin County’s Blind
Sequential Lineup Pilot Project. Cardozo Public Law,
Policy & Ethics Journal, 4,381–413.
Valentine, T., Pickering, A., & Darling, S. (2003).
Characteristics of eyewitness identification that predict
the outcome of real lineups. Applied Cognitive
Psychology, 17,969–993.Eyewitness Identification: Field Studies——— 291E-Cutler (Encyc)-45463.qxd 11/18/2007 12:42 PM Page 291