In Giles v. California, 554 U.S. 353, 128 S. Ct. 2678, 171 L. Ed. 2d 488 (2008), this Court recognized the common law exception to the Confrontation Clause of "forfeiture by wrongdoing," which allows prosecutors to introduce statements from an unavailable declarant when the defendant caused the unavailability "by design." The Sixth Circuit determined this "by design" element may include evidence of "mixed motives" — i.e. that the defendant procured the unavailability of the declarant for reasons other than their testimony at the instant trial.

When the prosecution seeks to invoke the forfeiture-by-wrongdoing exception and admit a statement without any protections afforded under the Confrontation Clause, must they prove that the defendant's primary purpose for making the declarant unavailable was to prevent their testimony in the proceeding for which the statement is being offered?

Whether the prosecution must prove the defendant's primary purpose for making the declarant unavailable was to prevent their testimony in the proceeding for which the statement is being offered to invoke the forfeiture-by-wrongdoing exception to the Confrontation Clause