501 F.2d 146 (9th Cir.1974) (same), United States v. Brown, 540 F.2d 1048 (10th Cir.1976) (same), and United States v. Thevis, 665 F.2d 616, 641 (5th Cir.1982), with United States v. Brownlee, 454 F.3d 131, 140-44 (3d Cir.2006) (reversible error to exclude expert testimony explaining problems inherent in stranger-to-stranger eyewitness identifications, finding that "expert testimony was the only method of imparting confidence in erroneous identifications”); United States v. Mathis, 264 F.3d 321, 340-42 (3d Cir.2001) (finding an abuse of discretion where district court excluded expert testimony on eyewitness identification and rejecting government's argument that the jury did not need an expert be aware of such factors); United States v, Harris, 995 F.2d 532, 534-35 (4th Cir.1993) (<HOLDING>); cf. United States v. Rodriguez-Felix, 450
holding court abused its discretion when it excluded psychologists testimony regarding host of identification issues among which was crossracial identification holding that where the opportunity for positive identification is good and not weakened by prior failure to identify and the witness is positive in his identification even after crossexamination identification need not be received with caution holding that agents testimony as to witnesss identification was not hearsay holding that instructions on crossracial identification required prospectively unless parties agree there was no crossracial identification recognizing a trend in recent years to allow such testimony and collecting cases in which such testimony was allowed in cases involving crossracial identification identification after a long delay identification after observation under stress and psychological phenomena as the feedback factor and unconscious transference