Mesarosh v. United States
Headline: Court orders new federal criminal trials after government admits its key informant’s testimony in other proceedings was unreliable, tainting convictions and affecting all five defendants.
Holding: Because the Government’s own informant later gave sworn statements shown to be unreliable, the Court found the trial tainted and ordered new trials for the defendants.
- Orders new federal trials for defendants whose convictions relied on the discredited informant.
- Requires prosecutors to disclose and reassess witness reliability in similar cases.
- Makes clear courts will not uphold convictions based on plainly tainted testimony.
Summary
Background
Five men were charged in federal court with conspiring under the Smith Act to advocate violent overthrow of the United States Government. After a lengthy trial they were convicted and the Third Circuit affirmed. Shortly before this Court’s scheduled argument the Solicitor General told the Court that one of the Government’s seven witnesses, Joseph Mazzei, had given sworn statements in other proceedings that the Government now doubted or believed to be untrue. The Government moved to send the case back to the trial court to reexamine Mazzei’s credibility; the defendants asked for a new trial.
Reasoning
The central question was whether the convictions were tainted by reliance on Mazzei’s testimony. The Court accepted the Government’s representations that parts of Mazzei’s post-trial sworn statements were contrary to known facts and that his overall credibility was discredited. Because his testimony was important—the Government conceded two convictions could not stand without it and the trial judge had admitted his testimony against all defendants—the Court held the trial was polluted and the only just result was to grant new trials rather than remand for limited inquiry.
Real world impact
The decision gives these defendants new trials and makes clear that convictions resting on a Government witness later shown to be unreliable will not be allowed to stand. The ruling shows that federal courts and prosecutors must confront and correct tainted testimony, and that appellate review can require retrial when a key informant’s credibility is destroyed. The opinion does not decide guilt or innocence on the merits.
Dissents or concurrances
A dissent by three Justices argued the Court should have remanded to the trial judge for a full hearing first. They thought the trial court was the proper forum to sort disputed facts about the witness and that the Solicitor General had not conceded perjury but only called for investigation.
Opinions in this case:
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