Evidence that is favorable to the defendant (exculpatory) and could impact the outcome of the defendant’s case (material) is often called “Brady material” because of the seminal 1963 U.S. Supreme Court case, Brady v. Maryland. In that case, the Supreme Court established a rule that prosecutors must disclose “Brady material” to the defense. The failure to disclose such material is a “Brady violation,” a violation of the U.S. Constitution.

Through Brady and its progeny, the Supreme Court has made clear that “Brady material” must be turned over to the defense in a timely manner, whether the defense requests it or not, and that a prosecutor’s good faith efforts to comply do not shield the state from a “Brady violation.” The Supreme Court has also held that “Brady material” includes not only affirmatively exculpatory evidence but also impeachment evidence and any consideration a witness may receive; it also includes evidence in the possession of law enforcement, even if prosecutors themselves do not possess it or even know about it.