What is the current state of the law on suppression of evidence in civil cases where the suppression was not deliberate in either of the senses of deliberation or deliberate misconduct?

There remains a third category of cases where the suppression was not deliberate in either of the senses we have included and no request was made, but where hindsight discloses that the defense could have put the evidence to not insignificant use. While we do not dispute that relief may sometimes be granted even in such cases, the standard of materiality must be considerably higher. This is because, as we said in Kyle v. United States, supra, "The pans contain weights and counterweights other than

[391 F.2d 148]

the interest in a perfect trial." Deliberate prosecutorial misconduct is presumably infrequent; to invalidate convictions in the few cases where this is proved, even on a fairly low showing of materiality, will have a relatively small impact on the desired finality of judgments and will deter conduct undermining the integrity of the judicial system. The request cases also stand on a special footing; the prosecution knows of the defense's interest and, if it has failed to honor this even in good faith, it has only itself to blame. Failure to appreciate the use to which the defense could place evidence in the prosecution's hands, or forgetfulness that it exists when a development in the trial has given it a new importance, are quite different. Since this must happen to the most scrupulous prosecutors and the issue of deterrence scarcely arises, the problems of the courts and the wider interests of society unite to require a substantially higher probability that disclosure of the evidence to the defense would have altered the result. To invalidate convictions in such cases because a combing of the prosecutors' files after the trial has disclosed evidence possibly useful to the defense but not likely to have changed the verdict would create unbearable burdens and uncertainties.

[391 F.2d 148]