The right of confrontation guaranteed by the Sixth Amendment to the Constitution of the United States bars the introduction against a criminal defendant of testimonial hearsay by a nontestifying declarant unless (i) the absent declarant is unavailable to testify at trial and (ii) the defendant had an adequate opportunity to cross-examine the absent declarant prior to trial.

United States v. Brown, 315 F.3d 929, 931-932 (8th Cir. 2003) (upholding trial court's admission of US Secret Service agent's testimony [about the Secret Service computerized database] as public record exception to the....An exception to the hearsay rule applies to the following records of government offices and agencies: (A) public records that set forth the activities of the government office or agency; (B) public records that set forth observations that a government office or agency was required to make and report but this exception does not apply in criminal cases to observations of police officers and other law enforcement personnel; or (C) in civil actions and proceedings and in criminal cases when offered against the government, factual findings resulting from an investigation made pursuant to authority granted by law, unless the sources of information or other circumstances indicate the untrustworthiness of such findings.

Fed. R. Evid. 608(b) ("Specific instances of the conduct of a witness, for the purpose of attacking or supporting the witness' character for truthfulness, other than conviction of....If a crime or act by a witness did not result in a criminal conviction but is probative of truthfulness and not unduly prejudicial, it may sometimes be used to impeach the witness.

United States v. DeCicco, 370 F.3d 206, 210-211 (1st Cir. 2004) (remanding for further proceedings in which trial court had excluded evidence of the March 1992 fire, on ground that such evidence was relevant and probative of accused's common scheme or plan to burn the Heard Street warehouse for the...Evidence of another crime, wrong, or act is not barred by the prohibition against circumstantial use of character if such other crime, wrong, or act is offered to prove the existence of a plan or scheme.