Samuel Gross wrote an amicus brief[i] in support of Willie Manning for his concluded case from 1993 (Jimmerson-Jordan murders). This summer Gross, writing more generally, highlighted “a terrible old rule that has done great harm to the accuracy of criminal trials, and will continue to do so.” This rule delayed Willie’s exoneration in his 1993 case, and remains relevant in his ongoing case.
Gross explains that in a criminal trial the government must disclose evidence that is favourable to the defense only if it is “material” (significant). A court determines that evidence is “material” only if it believes there is a “reasonable probability” that its disclosure would have produced a trial outcome that was more favorable to the defendant.
In other words, prosecutors may conceal evidence favourable to the defendant if they decide it is not sufficiently significant to influence the jury’s verdict.
Gross explains the bias this rule produces. Prosecutors cannot possibly know what impact the evidence in question will have on the jury; they may well be tempted to withhold the evidence to make their job easier, knowing that in all probability no one will ever know. As Gross says,
“If somehow it does come out, a court reviewing the case faces the same impossible question—what might have happened at trial if these facts had been known to the defense?—with an added twist: Judges are extremely reluctant to reverse jury verdicts and order new trials.”
In Willie’s concluded case the Oktibbeha County Circuit Court ruled that exculpatory canvass notes were not material. The Mississippi Supreme Court eventually overturned that ruling; but not before the initial decision had caused Willie considerable stress.
In Willie’s ongoing case he maintains that material, exculpatory evidence exists which the prosecution failed to provide e.g. secretly recorded phone conversations, and evidence revealing the great extent to which state witnesses were incentivized. Courts have not, so far, been troubled by the state’s concealment of this evidence.
Gross advocates radical action to restore confidence in the judicial process:
“Why not eliminate the “materiality” requirement entirely and treat access to exculpatory evidence like other aspects of a criminal defendant’s constitutional right to a fair trial? If exculpatory evidence is concealed, it’s a violation of the Constitution, period.”
[i] Willie Jerome Manning v. State of Mississippi. 2013-CA-00882. Brief of Amicus Curiae, Professor Samuel R. Gross, in Support of Appellant, Willie Jerome Manning. In the Supreme Court of the State of Mississippi. Dec 19, 2013. Web, Jan 3, 2013.