FRE 404(b) evidentiary doctrine is a bit of a mess. Complicating that mess is the government's claim that evidence is “inextricably intertwined” with the offense charged. Here is a recent footnote from a Fourth Circuit decision:
At all events, the intrinsic/extrinsic inquiry has ventured far from where it began. See Milton Hirsch, “ This New–Born Babe an Infant Hercules”: The Doctrine of “Inextricably Intertwined” Evidence in Florida's Drug Wars, 25 Nova L.Rev. 279, 280 (2000) (“[U]ntil about the year 1980, no one thought that evidence of uncharged crimes could be rendered admissible by the simple expedient of describing it as ‘inextricably intertwined’ with evidence of the crime or crimes actually pleaded in the indictment.”). As pointed out by the D.C. Circuit, “it cannot be that all evidence tending to prove the crime is part of the crime. If that were so, Rule 404(b) would be a nullity.” United States v. Bowie, 232 F.3d 923, 929 (D.C.Cir.2000). Yet, by characterizing evidence as “intrinsic,” federal courts, including this one, have allowed prosecutors to introduce evidence of uncharged bad acts free from Rule 404(b)'s protections, including limiting jury instructions and advanced notice of the government's intent to introduce the evidence. Fortunately, some courts have begun to recognize the harm caused by granting federal prosecutors such unmitigated leeway. See United States v. Gorman, 613 F.3d 711, 719 (7th Cir.2010) (abandoning the “inextricable intertwinement doctrine” because it “has outlived its usefulness” and “become overused, vague, and quite unhelpful”); United States v. Green, 617 F.3d 233, 248 (3d Cir.2010)(“[T]he inextricably intertwined test is vague, overbroad, and prone to abuse, and we cannot ignore the danger it poses to the vitality of Rule 404(b).”); Bowie, 232 F.3d at 927(“[I]t is hard to see what function this [intrinsic/extrinsic] interpretation of Rule 404(b)performs.”); see also United States v. Irving, 665 F.3d 1184, 1215 (10th Cir.2011) (Hartz, J., concurring) (stating that “the intrinsic/extrinsic dichotomy serves no useful function and consumes unnecessary attorney and judicial time and effort,” and that “the distinction between intrinsic and extrinsic evidence is unclear and confusing, and can lead to substituting conclusions for analysis”).
At bottom, the inextricably intertwined precedent is underthought and terrifically vague. If you are gong to trial, keep this footnote in your quiver.