Patterson v. United States

District of Columbia Court of Appeals · 2012 · Evidence

37 A.3d 230 (D.C. App. 2012)

Updated August 22, 2026

Evidenceeyewitness identificationexpert testimonycorroborative evidenceDyas testplain errorclosing argumentMonroe-Farrell

Facts

A robber approached Mira Kuczynska at close range, displayed a western-style revolver with a brown and dark yellow handle, took her purse, and fled. Nine days later she identified appellant in a photo array and also identified him at trial. The government also introduced corroborative evidence linking appellant to the robbery, including his attempt to use the victim's altered checks at a Giant store, stolen property found in a motel room associated with him, and a revolver in that room similar to the one the victim described. Appellant sought to present an expert on eyewitness identification and later claimed counsel was ineffective for not presenting other evidence, including evidence about a hand tattoo and another person's alleged confession.

Issue

Whether the trial court erred in excluding appellant's expert on eyewitness identification, in failing to conduct further inquiry into counsel or self-representation, and in not sua sponte correcting the prosecutor's closing remarks. Also, whether the court erred in denying appellant's § 23-110 motion without a hearing on his ineffective-assistance claims.

Rule

In deciding whether to admit expert testimony on eyewitness identification, the trial court exercises discretion under a case-specific inquiry into whether the testimony would assist the jury; although corroboration is not an element of the Dyas test, corroborative evidence is a legitimate consideration in evaluating whether exclusion is an abuse of discretion and may also render any assumed error harmless. A Monroe-Farrell inquiry is triggered only by a specific and detailed pretrial challenge to counsel's effectiveness, and a Faretta claim requires a clear positive demand to proceed without counsel. Unobjected-to prosecutorial argument is reviewed only for plain error. A § 23-110 ineffective-assistance claim may be denied without a hearing when the motion and record conclusively show no entitlement to relief, including where allegations would not warrant relief even if true.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In a robbery trial in Chicago, the victim identified Devin Cross as the gunman. Prosecutors also introduced evidence that Cross tried to use the victim’s stolen debit card the next day, and police found the victim’s backpack and a handgun matching the victim’s description in a Toledo apartment leased by Cross’s girlfriend and linked to Cross by his mail and clothing.

Cross offers a qualified psychologist to testify about factors that can reduce the accuracy of stranger identifications. The trial judge excludes the expert after concluding the jury would not need that assistance in light of the corroborating evidence. On appeal, what is the strongest argument for affirmance?

Explanation. The majority held that corroboration is not itself an element of the Dyas test, but it is a legitimate consideration in deciding whether exclusion was an abuse of discretion because the key case-specific question is whether the expert would assist the jury. Where substantial corroborative evidence supports identity, exclusion may fall within the trial court’s discretion.