Similarly, beginning with then Judge Sotomayor's opinion for the Second Circuit in United States v. Saget, 377 F.3d 223 (2d Cir. 2004), our sister circuits have relied on definitions of "testimonial" akin to that which we tendered in Summers to hold "a declarant's statements to a confidential informant, whose true status is unknown to the declarant, do not constitute testimony within the meaning of Crawford." Saget, 377 F.3d at 229 (Sotomayor, J.); accord Johnson, 581 F.3d at 325 (recognizing that a declarant's statement unwittingly made to a confidential informant wearing a wire is not testimonial); United States v. Watson, 525 F.3d 583, 589 (7th Cir. 2008) (same); United States v. Udeozor, 515 F.3d 260, 270 (4th Cir. 2008) (same); United States v. Underwood, 446 F.3d 1340, 1347 (11th Cir. 2006) (same); United States v. Hendricks, 395 F.3d 173, 182-84 (3d Cir. 2005) (same).

And insofar as a trial court excludes evidence under Rule 403, we afford the court broad discretion — overturning an evidentiary ruling only "under the most extraordinary circumstances, where that discretion has been plainly abused." See United States v. Udeozor, 515 F.3d 260, 265 (4th Cir. 2008).

This Rule "is a rule of inclusion, generally favoring admissibility." United States v. Udeozor, 515 F.3d 260, 264-65 (4th Cir. 2008) (cleaned up). In other words, "[w]here evidence is probative, 'the balance under Rule 403 should be struck in favor of admissibility, and evidence should be excluded only sparingly.' "

We have previously noted that "[i]t is not an easy thing to overturn a Rule 403 ruling on appeal." United States v. Udeozor, 515 F.3d 260, 264 (4th Cir. 2008). Where the evidence is probative, "the balance under Rule 403 should be struck in favor of admissibility, and evidence should be excluded only sparingly."

"It is not an easy thing to overturn a Rule 403 ruling on appeal." United States v. Udeozor, 515 F.3d 260, 264 (4th Cir. 2008). Where the evidence is probative, "the balance under Rule 403 should be struck in favor of admissibility, and evidence should be excluded only sparingly."

United States v. Aramony, 88 F.3d 1369, 1378 (4th Cir. 1996) (internal quotation marks omitted). "It is not an easy thing to overturn a Rule 403 ruling on appeal," United States v. Udeozor, 515 F.3d 260, 264 (4th Cir. 2008). Where the evidence is probative, "the balance under Rule 403 should be struck in favor of admissibility, and evidence should be excluded only sparingly."

In contrast, statements that demonstrate a declarant's "knowledge of significant details about the crime" or "implicate him in a conspiracy" are "intrinsically inculpatory." Dargan, 738 F.3d at 649 (quotations omitted); see United States v. Udeozor, 515 F.3d 260, 267 (4th Cir. 2008) ; Jordan, 509 F.3d at 202.

United States v. Udeozor, 515 F.3d 260, 265 (4th Cir. 2008) (quoting United States v. Simpson, 910 F.2d 154, 157 (4th Cir. 1990))).

Though phrased in terms of exclusion, "Rule 403 is a rule of inclusion, generally favoring admissibility" and giving the district court "wide discretion to determine what evidence is admissible" thereunder. United States v. Udeozor, 515 F.3d 260, 264-65 (4th Cir. 2008). On appeal, "we review a district court's admission of evidence over a Rule 403 objection under a broadly deferential standard," finding error only "under the most extraordinary circumstances, where that discretion has been plainly abused."

United States v. Jordan, 509 F.3d 191, 203 (4th Cir.2007) (internal quotation marks omitted). Second, the statements are intrinsically inculpatory to the extent they demonstrate Harvey's knowledge of “significant details about the crime,” Williamson, 512 U.S. at 603, 114 S.Ct. 2431, and “implicate him in a conspiracy,” United States v. Udeozor, 515 F.3d 260, 267 (4th Cir.2008). Harvey's admission that he committed the robbery with the assistance of two co-conspirators not only revealed his knowledge of the number of participants, but also potentially subjected him to conspiracy liability.