Discovery obligations apply to court-martial motions practice, for example when there is to be a suppression hearing.
The government has a mandatory duty to disclose evidence in its possession that is favorable to the defense, "either because it was exculpatory or of impeachment value . . . ." . The government breaches the duty established by Brady v. Maryland, 373 U.S. 83 (1963), and its progeny, including Giglio v. United States, 405 U.S. 150 (1972), when it withholds such evidence, either willfully or inadvertently, and the withheld evidence is found to be "material." Id. In the context of non-disclosed impeachment evidence, materiality is assessed in terms of whether the reliability of the witness in question may well be determinative of the outcome of the proceedings. See Pennsylvania v. Ritchie, 480 U.S. 39 (1987). That is, the evidence must be such that "there is a reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have been different." (quoting United States v. Bagley, 473 U.S. 667, 682 (1985)). Stated otherwise, "the relevant question is: ‘when viewed as a whole and in light of the substance of the prosecution’s case, did the government’s failure to provide . . . [the] Brady impeachment evidence to the defense . . . lead to an untrustworthy [result]. . . ." (some citations omitted).
United States v. Best, No._________, 2009 U.S. Dist. LEXIS 119802, at *19–20 (M.D. Pa. Dec. 23, 2009).