The Single Photo and the Eight Percent Discrepancy
At 11:40 p.m. a man with a handgun robs a convenience store. The clerk, 62, sees his face for six to eight seconds in fluorescent light at roughly 12 feet. She describes him as 5 feet 10 inches, 170 pounds, in a dark hoodie. Two hours later an officer brings a single photograph of Mr. D., taken from a prior arrest, to the store and says, We think this is the guy, is this him? She says she is about 80 percent sure. After the officer mentions that Mr. D. has a record and was picked up near the store, she says she is certain. Mr. D. is 6 feet 4 inches, 240 pounds, and Black; the clerk is white. The prosecution asks whether the identification is reliable under the totality of the circumstances; the defense asks you to consult on the array procedure and on testifying about confidence.
1. Separate the estimator and system variables in this case and assess their relative weight.
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Estimator variables are those the justice system cannot control; system variables are those it can, and they are where the criticism belongs.
Estimator factors here:
- Exposure was short (six to eight seconds) and under stress with a weapon present, which research associates with narrowed attention on the weapon rather than the face.
- The cross-racial identification (white witness, Black suspect) is associated with elevated error rates, particularly at brief exposure.
- The description discrepancy is substantial: four inches and 70 pounds is a large error for a face-to-face encounter at 12 feet.
- Lighting was adequate, which helps, and the interval before the procedure was short, which helps.
System factors:
- A single-photograph show-up is inherently suggestive. There were no fillers, so the procedure contained no test of whether the officer's suspicion or the suspect's appearance was driving the choice.
- The administering officer knew who the suspect was and communicated that knowledge verbally and nonverbally.
- The instruction we think this is the guy presupposes guilt and invites confirmation.
- Post-identification information about the record and the arrest location was feedback that inflates confidence and retrospective reports of certainty.
Weighting: the system variables are severe and are the court's proper concern, because they contaminate the only evidence of certainty the state can offer. The estimator variables, especially the cross-racial and weapon-focus issues and the physical description mismatch, independently reduce reliability.
2. How should the show-up and the shift from 80 percent to certain be analyzed under the legal reliability standard?
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Under Neil v. Biggers and Manson v. Brathwaite, courts weigh the opportunity to view, the degree of attention, the accuracy of the prior description, the witness's level of certainty at the time of the identification, the length of time between the crime and the identification, and the practical necessity of the procedure. The Supreme Court has treated a suggestive procedure as a factor to be weighed against reliability rather than as an automatic bar.
Apply each. Opportunity: short but reasonably lit and close. Attention: likely compromised by the weapon. Description: poor fit on height and weight, an accuracy problem that cuts against reliability. Time: two hours, favorable. Certainty: this is where the case turns.
The 80 percent statement was made before feedback; the certainty statement came after the officer told her about the prior record and the nearby arrest. That sequence is the textbook demonstration that confidence is malleable and that post-identification feedback inflates both expressed certainty and the witness's recollection of how certain she was at the time. An initial 80 percent is itself equivocal and inconsistent with a confident identification.
The defensible position for the consultant: the procedure was impermissibly suggestive, the certainty evidence is contaminated and should not be treated as an independent indicator of accuracy, and any reliability finding resting on that certainty is unsound. A curative alternative would have been a properly constructed, double-blind lineup with unbiased instructions, administered before any feedback.
3. What are the limits of your expert testimony, and what would you decline to say?
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Testimony should educate the fact finder on general principles and, if permitted, apply them to the features of this case. It should not resolve the case.
Appropriate content
- The distinction between estimator and system variables.
- Research on weapon focus, stress, brief exposure, and cross-racial identification.
- The weak confidence-accuracy relationship, and the specific finding that post-identification feedback inflates confidence without improving accuracy.
- Best-practice eyewitness procedures, including double-blind administration, a sufficient number of fillers, unbiased pre-identification instructions, and immediate confidence statements taken before feedback.
Inappropriate content
- An opinion that the clerk is wrong or that Mr. D. is innocent; that usurps the jury's role.
- A numerical probability that this witness is accurate; no research supports applying group statistics to an individual identification.
- Testimony beyond your expertise or beyond the published literature.
Procedural preparation Expect a Daubert or state-equivalent challenge. Be ready to cite the underlying research base, to acknowledge that studies vary and that eyewitness science is probabilistic, and to explain that you are not opining on guilt. Also note that the initial wording of the identification and the timing of the confidence statements should be preserved in the officers' reports and any body-camera footage; if that record is missing, say the data are insufficient to evaluate contamination rather than fill the gap with speculation.