After viewing a crime or event,
eyewitnesses are asked to identify the
perpetrator from a list of suspects.
Unfortunately, eyewitness memory is
unreliable, and lineups often contain
some form of bias.
Currently there are two lineups styles that
law enforcement can use with witnesses:
Witnesses can also be shown only a
picture of the suspect. This is called a
Simultaneous- all suspects featured in the
lineup are shown at once.
› Higher identification rate: Both positive and
› Potential for comparative judgments—
choosing the face who looks “most like” the
1 2 3
4 5 6
Sequential- The people featured are
shown one at a time, and the witness
must say whether or not the person
currently shown is the perpetrator.
› Lower Identification rate: Both positive and
see a suspect
photo one at a
time in a format
such as this.
Most police municipalities do not have formal rules or guidelines about which type of lineup to use, or how to interact with witnesses.
Most memory researchers recommend using a sequential lineup.
The prevailing theory is that sequential presentation reduces false identifications, without concurrently reducing true identifications.
In the present research, we propose a third type of lineup--slideshow.
The witness can view each face as many times as needed, however only one face is on the screen per time.
Each picture is shown for 6 seconds before the presentation automatically moves on to the next picture.
The slideshow runs on a continuous loop until the witness makes a decision.
The witness picks a starting point at
› This is accomplished by selecting a card at
random with a colored shape on it.
› This shape corresponds to one of the shapes
we have associated with each of the
› When no picture is obviously first or last we can control for possible sequence effects.
To identify the suspect, the witness
confirms the name
and color of the
Example: “Blue Star”
The slideshow lineup will produce the
same number of correct IDs as the
› Current thinking is that simultaneous lineups
produce more IDs because witnesses have
time to compare all the faces and “pick the
› We hypothesize that the benefit will still exist
with multiple exposures but no opportunity to
directly compare faces.
101 general psychology students from
the University of Mary Hardin-Baylor
participated in our experiment.
The experiment was double-blind
› Neither witnesses nor proctors knew who the
suspects were in the lineups.
We split participants into 3 groups:
› Simultaneous Lineups(31)
› Sequential Lineups (32)
› Slideshow Lineups (38)
We showed a 45 second video of a
mock car jacking to all participants.
They were given two 5-minute
questionnaires to create a delay
between the video and the lineup.
A target present lineup was shown
containing 6 suspects.
› Target present means the true suspect was
present in the lineup.
The participant’s selection was
accompanied by a self-evaluated
confidence level based on their
› The confidence ratings varied from 0-100%.
The simultaneous and slideshow lineups
produced a similar rate of correct
identifications, supporting our hypothesis.
The sequential lineup produced a mean
correct ID rate of 31%.
› This challenges previous findings suggesting
that sequential presentation of a lineup does
not significantly reduce the likelihood of correct identifications.
So far, we have supported the
hypothesis that simultaneous and
slideshow presentation of a target-
present lineup produces similar results.
Next, we need to see what happens with
We hope that slideshow presentation of
a target-absent lineup will lead to fewer
false identifications than simultaneous
presentation of a target-absent lineup.
This would create a lineup format that
merges the benefits of both simultaneous
and sequential presentation.
Sponsor: Trent Terrell Ph.D
› Thomas Via
› Kristina Zufall
› Hope Underwood