April 16, 2019
from the United States District Court for the Northern
District of Illinois, Eastern Division. No. 15 CR 573 - Sara
L. Ellis, Judge.
EASTERBROOK, KANNE, and SCUDDER, Circuit Judges.
EASTERBROOK, CIRCUIT JUDGE.
convicted Myshawn Bonds of bank robbery, 18 U.S.C.
§2113(a), and a judge sentenced him to sixty months'
imprisonment plus three years' supervised release. The
evidence against him included the testimony of Kira Glass, a
fingerprint examiner in the FBI's Latent Print Operations
Unit. Glass concluded that Bonds's fingerprints appeared
on the demand notes used in the two robberies.
the Latent Print Operations Unit incorrectly identified
Brandon Mayfield as a person whose fingerprints suggested
involvement in a terrorist bombing in Spain. Mayfield was
arrested and held for more than two weeks as a material
witness, until the FBI acknowledged that its assessment
resulted from operational errors. The United States released
Mayfield, apologized, and paid him substantial compensation.
Bonds wanted to use this episode to illustrate for the jury
the potential for mistakes in the application of a method
that fingerprint analysts dub ACE-V, for analysis,
comparison, evaluation, and verification. That method
miscarried for Mayfield, and Bonds contended that it could
miscarry for him too.
district judge concluded that evidence about Mayfield's
arrest in 2004 would take the trial far afield from the
question whether Bonds robbed two banks in 2015. The judge
permitted Bonds to cross-examine Glass about the reliability
of the ACE-V method and to present other evidence suggesting
that the approach is more error-prone than jurors are likely
to believe after watching forensic labs operate to perfection
on television. Evidence about one particular error, the judge
concluded, would be more distracting and time consuming than
its incremental value could justify.
contends that the district court's decision to exclude
evidence about Mayfield's mistaken identification and
arrest violated the Confrontation Clause of the
Constitution's Sixth Amendment. United States v.
Rivas, 831 F.3d 931 (7th Cir. 2016), rejected an
identical contention, holding that a district court did not
violate the Constitution when excluding evidence about the
Mayfield situation. Bonds asks us to distinguish
Rivas on the ground that Glass works in the same FBI
division that mistakenly identified Mayfield, but Bonds does
not contend that Glass was involved in that error. Guilt by
association would be a poor reason to deny a district judge
the discretion otherwise available under Fed.R.Evid. 403.
counsel suggested at oral argument that jurors respond more
strongly to concrete examples than to data about error rates.
That may well be true-but it is a reason to limit the use of
extrinsic evidence, not to require judges to admit it.
Presenting jurors with details of one wrongful imprisonment
(especially on a mistaken charge of terrorism) would appeal
to their emotion rather than to their reason. Emotional
responses can be strong, but reason should underlie a
had ample opportunity to supply the jury with evidence about
the reliability of the ACE-V method, including the extent to
which changes the FBI made in the last decade have improved
its reliability. Shortly after the Mayfield fiasco the
National Research Council concluded that the ACE-V method is
too subjective and too unreliable to deserve the label
"scientific." Strengthening Forensic Science in
the United States: A Path Forward 136-45 (2009). More
recently, the President's Council of Advisors on Science
and Technology concluded that changes in ACE-V have bolstered
its accuracy. Forensic Science in the Criminal Courts:
Ensuring Scientific Validity of Feature-Comparison
Methods 87-103 (2016). This report concluded that the
error rates shown by well-designed studies ranged from 1 in
18 to 1 in 604. (These are rates of false
positives-incorrectly declaring a match when the prints
differ-taking account of statistical confidence intervals.)
The bottom line (id. at 101-02; emphasis in
Foundational validity. Based largely on two
recent appropriately designed ... studies, [we find] that
latent fingerprint analysis is a foundationally valid
subjective methodology-albeit with a false positive rate that
is substantial and is likely to be higher than expected by
many jurors based on longstanding claims about the
infallibility of fingerprint analysis.
Conclusions of a proposed identification may be
scientifically valid, provided that they are accompanied by
accurate information about limitations on the reliability of
the conclusion- specifically, that (1) only two properly
designed studies of the foundational validity and accuracy of
latent fingerprint analysis have been conducted, (2) these
studies found false positive rates that could be as high as 1
error in 306 cases in one study and 1 error in 18 cases in
the other, and (3) because the examiners were aware they were
being tested, the actual false positive rate in casework may
be higher. At present, claims of higher accuracy are not
warranted or scientifically justified. Additional... studies
are needed to clarify the reliability of the method.
Validity as applied. Although we conclude
that the method is foundationally valid, there are a number
of important issues related to its validity as applied.
Confirmation bias. Work
by FBI scientists has shown that examiners typically alter
the features that they initially mark in a latent print based
on comparison with an apparently matching exemplar. Such
circular reasoning introduces a serious risk of confirmation
bias. Examiners should be required to complete and document
their analysis of a latent fingerprint before
looking at any known fingerprint and ...