Evidence that is relevant to a material fact is relevant for purposes of Federal Rule of Evidence 401 and the federal law of evidence even though the material fact is undisputed.

Cf. United States v. Valuenzuela-Bernal, 458 U.S. 858, 872-873 (1982) (deportation of possible witness did not violate criminal defendant's constitutional right to compulsory process or due process; "To summarize, the responsibility of the Executive Branch faithfully to execute the immigration...The prohibition, grounded in the Compulsory Process Clause, against deliberate government action that deprives a criminal defendant of the relevant and material exculpatory testimony of a witness may effectively limit the government's use of hearsay evidence against a criminal defendant.

Fed. R. Evid. 104(b) ("When the relevancy of evidence depends upon the fulfillment of a condition of fact, the court shall admit it upon, or subject to, the introduction of evidence sufficient to support a finding of the fulfillment of the condition.").The relevance of proffered evidence may depend on a "condition." A "condition" is some fact other than the fact that the proffered evidence is meant to establish.

United States v. Archer, 843 F.2d 1019, 1023 (7th Cir. 1988) (upholding trial court's ruling which allowed the government to introduce evidence of accused's involvement in prior escape plans where it demonstrated that accused "had a profound awareness of security measures and various escape methods and...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.