Expert evidence based on or involving mass spectrometry and related sciences is insufficiently reliable to satisfy the requirements of Federal Rule of Evidence 702 or comparable State rules for the admissibility of expert evidence.

United States v. Schreane, 331 F.3d 548, 563-565 (6th Cir. 2003) (upholding trial court's ruling which allowed Officer Topping's testimony [about Duckett's statement during the stop] as an excited utterance because "Officer....A statement can qualify as an excited utterance for purposes of the hearsay exception created by by Federal Rule of Evidence 803(2) or a comparable State rule only if the declarant (the maker of the statement) personally perceived the exciting event or condition to which his or her statement relates.

United States v. Williams, 527 F.3d 1235, 1247 (11th Cir. 2008) (upholding trial court's admission into evidence of accused's history of non-compliance with federal grant regulations because accused claimed good faith defense and inadvertent mistake and rebuttal evidence was offered as "to prove...Evidence of a criminal or wrongful act apart from the act that at issue at trial Is not barred by the prohibition against circumstantial use of character if intent, knowledge, mistake, or accident is a legally-material factual issue, the opposing party suggests the non-existence of knowledge or urges mistake or accident as a defense, and evidence of another crime, wrong, or act is offered to prove the knowledge or the absence of mistake or accident by a criminal defendant or other person.

Charter v. Chleborad, 551 F.2d 246, 248-249 (8th Cir. 1977) (holding, in plaintiff patient's medical malpractice action against defendant surgeon, that expert witness's testimony on the subject of insurance was....Although Federal Rule of Evidence 411 bars the use of liability insurance or its absence on the issue of negligence or wrongful conduct, evidence about the existence or non-existence of liability insurance my be used to impeach a witness by showing the witness's bias or prejudice.