Determinations of the relevance of evidence and of claims that evidence is unduly prejudicial are mainly for the trial court and are reviewable only for abuse of discretion.

Johnson v. Elk Lake School District, 283 F.3d 138, 152-155 (3d Cir. 2002) (civil action for sexual harassment and abuse; issue: admissibility under Federal Rule of Evidence 415 of another sexual offense; after extensive discussion court of appeals reluctantly concludes that the "sufficient to support a...Evidence of a condition upon which the relevance of evidence depends is sufficient if a reasonable trier (such as a jury) can find by a preponderance of the evidence that the condition exists.

Fed. R. Evid. 103(a) ("(a) Effect of erroneous ruling. Error may not be predicated upon a ruling which...excludes evidence unless a substantial right of the party is affected, and (1) Objection. - In case the ruling is one admitting evidence, a timely objection or motion to strike appears of record, stating the specific ground of...If a trial court overrules an objection to evidence, an appellate court will review the trial court's ruling only if the opponent made a specific objection at trial; if the opponent of the evidence made a general objection and the trial court overruled the objection, it will be said that the opponent waived or forfeited its claim of error by making a general objection.

United States use of Carter Equipment Co. v. H.R. Morgan, Inc., 544 F.2d 1271, 1273 (5th Cir. 1977) (holding that statements about the signing of the invoices by defendant subcontractor constituted nonverbal conduct which was intended as an assertion, and....A "statement" for purposes of the hearsay prohibition against the admission of hearsay statements is (1) an oral or written assertion or (2) nonverbal conduct of a person, if it is intended by the person as an assertion.