For purposes of the hearsay exceptions created by Federal Rule of Evidence 804 or a comparable State rule a declarant is "unavailable" within the meaning of Rule 804(b) or a comparable State rule if the declarant is unable to be present or to testify at the hearing because of death or then existing physical or mental illness or infirmity; but a declarant is not "unavailable" if the declarant's absence is due to the procurement or wrongdoing of the proponent of a statement for the purpose of preventing the witness from attending or testifying.

Cf. United States v. Jackson, 208 F.3d 633, 637 (7th Cir. 2000) (upholding trial court's exclusion of internet postings as a hearsay exception under Federal Rule of Evidence 803(6) as business records of the supremacy....There is a hearsay exception for a memorandum, report, record, or data compilation, in any form, of acts, events, conditions, opinions, or diagnoses, made at or near the time by, or from information transmitted by, a person with knowledge, if kept in the course of a regularly conducted activity of a business, institution, association, profession, occupation, or calling if it was the regular practice of that business, institution, association, profession, occupation, or calling to make the memorandum, report, record or data compilation, unless the source of information or the method or circumstances of preparation indicate lack of trustworthiness.

United States v. Hernandez-Rivas, 348 F.3d 595, 600 (7th Cir. 2003) (upholding trial court's admission of co-conspirator's testimony about the source of the cocaine because "conversations identifying actors within the....A statement falls within the hearsay exemption for statements of co-conspirators only if the statement was made in furtherance of the conspiracy.

United States v. Armendariz-Mata, 949 F.2d 151, 154-155 (5th Cir. 1991) (upholding trial court's admission of government's evidence of accused's drug trafficking activities and his association with a drug trafficker because accused, by raising the entrapment defense, placed his predisposition at issue and...A subjective entrapment defense makes an accused's criminal liability contingent on a finding of the accused's predisposition or the accused's lack of predisposition to commit the crime charged and since criminal predisposition is a character trait, the defense of subjective entrapment makes accused's character an element of either a defense or a criminal charge, evidence of accused's criminal predisposition -- including evidence in the form of reputation, opinion, and evidence of specific instances of accused's conduct -- is not barred by the rule against the use of a person's character to show the person's conduct.