Giglio evidence refers to any information or material that may be used to impeach the credibility, testimony, or character of a prosecutor’s witness in a criminal case. In Giglio vs United States, John Giglio was convicted of using forged money orders with the assistance of Robert Taliento. The government, however, made a deal with Taliento to testify for them against Giglio in exchange for his immunity against prosecution. The jury and defense were unaware of this deal and ultimately Giglio was convicted. This deal was discovered after Giglio’s conviction and his defense team sought to overturn the jury’s decision based on the concealment from the government making Taliento’s testimony unreliable. In 1972, the case had reached the Supreme Court where they ruled that the failure to inform the jury on any agreements the government makes with any witness is a violation of a defendant’s due process rights, and therefore warranted a new trial.
Giglio evidence as a defense
Giglio evidence or material is a powerful tool to be aware of and use to defend your case or lead a successful post conviction appeal. An officer involved in a defendant’s arrest, for example, can be barred from testifying through a Giglio letter if the officer lacks integrity and credibility like concealing evidence in the past or any other misconduct. Other examples that must be presented by the prosecutor are: