Defendants have the same right to offer Rule 404(b) evidence as prosecutors, and they are not required to give pretrial notice under the Federal Rules of Evidence. When defendants offer this evidence, they attempt to prove that someone else is guilty of the crime attributed to them. This often is referred to as reverse Rule 404(b) evidence. Some defense evidence will be admitted - indeed the Confrontation Clause or Compulsory Process Clause may require admission in some cases - but not all defense evidence will be admitted. The issue is where to draw the line between admissible and inadmissible evidence. Two recent cases help to provide an answer. In United States v. Montelongo the court held that the defendant had a constitutional right to explore another person's possible guilt. In United States v. Seals, the court found that the evidence was irrelevant and appropriately excluded.
GW Paper Series
GWU Law School Public Law Research Paper No. 215; GWU Legal Studies Research Paper No. 215
Stephen A. Saltzburg, Trial Tactics: Reverse Rule 404(b) Evidence: Parts I and II, 20 Crim. Just. (2006).