U.S. v. Rivas

In prosecution on drug conspiracy and unlawful possession of firearm charges, Dist. Ct. did not err in precluding defendant from cross-examining govt. fingerprint examiner (who identified defendant’s latent partial fingerprint on gun by using ACE-V side-by-side comparison technique) by questioning said examiner about different examiner’s erroneous conclusion in prior case, where said examiner used same technique. Ct. rejected defendant’s claim that his Confrontation Clause rights were violated because he could not question examiner about prior case, since instant examiner was not examiner in prior case and defendant otherwise was able to question examiner about reliability of ACE-V technique. Moreover, instant limitation did not prevent jury from fully evaluating examiner’s testimony.