Giglio evidence is a type of exculpatory evidence that might help a criminally accused cast sufficient doubt on his or her guilt as to obtain an acquittal from a jury. Giglio evidence is named after the US Supreme Court case Giglio v. US, 405 U.S. 150 (1972). Giglio evidence is a type of evidence that might help impeach or cast doubt on the truthfulness of prosecution witnesses.

In Giglio, the accused was charged and convicted of passing forged money orders. However, it turns out that the key witnesses against Giglio — an uncharged alleged co-conspirator named Robert Taliento — had been promised that he would not be prosecuted if he testified for the Government. As explained by the court, the prosecution’s case depended almost entirely on Taliento’s testimony; without it there could have been no indictment and no evidence to carry the case to the jury. As such, Taliento’s credibility as a witness was a crucial factual issue in the case and Giglio’s criminal defense team — and the jury — were entitled to know about the immunity deal. Giglio’s defense team might have been able to convince the jury that the Taliento’s testimony was unreliable and, maybe, that would have been sufficient for a “not-guilty” verdict

The immunity deal was discovered after Giglio was convicted. Giglio’s defense team sought to overturn the conviction based on the government’s failure to provide and concealment of the immunity deal. Eventually, the case reached the US Supreme Court. The court overturned Giglio’s conviction and sent the case back for a new trial. In making its decision, the court assumed “as true” that there had been an immunity deal with Taliento although there was a conflict about the existence of an immunity deal. That issue was to be taken up during the new trial proceedings.

Since Giglio was decided, courts have held that a broad range of promises and benefits provided by prosecutors must be disclosed to defense counsel for purposes of possible impeachment of testimony from the prosecutor’s witness. Basically, any sort of immunity or benefit must be disclosed including:

• Immunity from prosecution in the pending case or other cases and other types of non-prosecution agreements/promises
• Dropped or reduced charges
• Expected or promises of reduced sentencing
• Assistance — of any sort — with a criminal proceeding in another jurisdiction
• Assistance — of any sort — with any type of governmental investigation
• Agreements or promises regarding forfeiture of assets
• Benefits or promises related to immigration status
• Letters or assistance of any sort regarding pardons, clemency or substantive positive recommendations or referrals for any purpose including employment, housing, etc.
• Other types of relocation or employment assistance
• Any of the foregoing provided for a family member of the witness

The types of exculpatory evidence that must be disclosed pursuant to the Giglio is not limited to benefits provided or offered to a government witness. Giglio also requires prosecutors to turn over other types of evidence that might be exculpatory including known facts that could demonstrate:

• Bias or animosity toward the criminally accused
• Bias or animosity toward a group of which the defendant is a member or is affiliated
• Relationship with a victim of the crime being charged
• Known but uncharged criminal conduct
• Prior convictions
• Known substance abuse or mental health issues or other issues that could affect the witness’s ability to perceive and recall events

As was the case in Giglio, failure of the prosecution to disclose this type of exculpatory evidence can be the basis for a successful post-conviction appeal.

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For more information, contact the criminal defense and post-conviction appeal team at the Federal Criminal Law Center. Our firm knows how to fully assess an individual’s case and how to identify the strongest grounds for appeal. Contact us today by calling (404) 633.3797 or by completing our quick and convenient online form. Remember, there are short-time deadlines for filing an appeal. Contact us today.