§ 22.05 IMPEACHMENT: SENSORY AND MENTAL DEFECTS

• Jurisdiction: United States

§ 22.05. IMPEACHMENT: SENSORY AND MENTAL DEFECTS

Although there is no federal rule on this type of impeachment, it is quite common. Any sensory or mental defect that might affect a witness's capacity to observe, recall,⁶⁰ or relate the events about which the witness has testified is admissible to impeach⁶¹ — for example, a nearsighted person sans eyeglasses identifying a person at a distance, or a colorblind person testifying about whether a traffic light was red or green. Mental condition is sometimes relevant to credibility.⁶² Often, however, it is not,⁶³ depending on the condition's relationship to credibility.⁶⁴

In addition, evidence that the witness was under the influence of alcohol or drugs at the time of the event⁶⁵ or the trial⁶⁶ falls within this category, but evidence of alcoholism or addiction generally does not.⁶⁷

Extrinsic evidence. As for extrinsic evidence (i.e., the testimony of other witnesses), there is no hard and fast rule. Sensory and mental defects often can be elicited through cross-examination, in which case the admissibility of extrinsic evidence should be regulated by the trial court under Rule 403.⁶⁸

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Notes:

^[60] Cf. Delaware v. Fensterer, 474 U.S. 15, 20 (1985) (defense counsel's cross-examination "demonstrated to the jury that [the expert] could not even recall the theory on which his opinion was based").

^[61] E.g., United States v. Ciocca, 106 F.3d 1079, 1082 (1st Cir. 1997) ("Ciocca was able to place before the jury ample evidence regarding Caporino's ability to remember the events that transpired prior to and after his accident.").

^[62] See United States v. Love, 329 F.3d 981, 984 (8th Cir. 2003) ("Here the nature of the psychological problem in question is memory loss — a condition that implicates Thomas's ability 'to comprehend, know and correctly relate the truth.'"); United States v. Gonzalez-Maldonado, 115 F.3d 9, 15 (1st Cir. 1997) ("It is well established that a witness' mental state can be relevant to the issue of the witness' credibility. . . . Dr. Fumero would have testified that Robles, as a result of his illness, was prone to exaggeration.").

^[63] E.g., United States v. Smith, 77 F.3d 511, 516 (D.C. Cir. 1996) ("Of course, a history of mental illness is not necessarily admissible as impeachment evidence."); Boggs v. Collins, 226 F.3d 728, 739 (6th Cir. 2000) ("While mental illness can indeed be relevant to a witness's credibility, courts hold that the decision of whether or not to allow in evidence of a...