Although settlement negotiations and offers are inadmissible (i) to show the validity or invalidity of a claim when validity is in dispute, (ii) to show the amount of damages when the amount is in dispute, or (iii) to impeach by showing a prior inconsistent statement or specific contradiction, settlements, settlement offers, and settlement negotiations are admissible if they are offered for other purposes.

Burns v. City of Des Peres, 534 F.2d 103, 112 n.9 (8th Cir. 1976) (holding, in plaintiff applicant's action against defendant ciity and other officials for abridgement of zoning rights, that evidence of compromise....Settlement offers and statements made during settlement negotiations are inadmissible if such offers and statements are offered to (i) show the validity or invalidity of a claim when the validity of the claim is in dispute, (ii) show the amount of damages when the amount of the claim is in dispute, or (iii) to impeach a witness by showing a prior inconsistent statement or specific contradiction.

Fed. R. Evid. 406 advisory committee's note ("When disagreement has appeared, its focus has been upon the question what constitutes habit" rather than on the admissibility of habit "and the reason for this is readily apparent. The extent to which instances must be multiplied and consistency of behavior maintained in order to rise to the...A course of conduct can constitute habit for purposes of Federal Rule of Evidence 406 and state counterparts to Rule 406 only if the conduct is highly regular or practically invariable.

United States v. Reyes, 362 F.3d 536, 540 (8th Cir. 2004) (upholding trial court's admission of a co-conspirator's statements as recounted by an agent which did not violate defendant's Confrontation Clause rights....The right of confrontation guaranteed by the Confrontation Clause of the Sixth Amendment to the U.S. Constitution puts no constraints on the admissibility of nontestimonial hearsay statements; the federal constitutional right of confrontation does not apply to such statements.