Is Federal Rule of Evidence 404(b) a rule of inclusion or exclusion?

QUESTION PRESENTED Federal Rule of Evidence 404(b) permits the admission of evidence of any other crime, wrong or act to prove a criminal defendant’s motive, opportunity, intent, preparation, plan, knowledge identity, absence of mistake, or lack of accident. The Second, Eighth, Ninth, Eleventh, and D.C. Circuits characterize this as a rule of inclusion, and as a result, other-acts evidence is routinely admitted. The Third, Fourth, and Seventh Circuits, however, reason that Rule 404(b) is a general rule of exclusion, meaning that it confers no presumption of admissibility. Is Federal Rule of Evidence 404(b) a rule of inclusion or exclusion? 1