Suppression of Witnesses or Evidence
Suppression of witnesses or evidence occurs when a prosecutor deliberately withholds, conceals, or obstructs access to testimony, documents, physical items, or other material information that is favorable to the defense, relevant to guilt or punishment, or necessary for a fair adjudication. Such conduct directly violates due process and undermines the integrity of judicial proceedings.
Scope:
Witness Suppression: Preventing defense access to witnesses, discouraging witnesses from testifying, or failing to disclose witness identities.
Evidence Withholding: Concealing exculpatory or mitigating material, even if not requested by the defense.
Access Obstruction: Imposing improper restrictions on discovery, delaying disclosure to limit effective use at trial, or providing evidence in unusable formats.
Non-Disclosure of Impeachment Evidence: Withholding information that would undermine the credibility of a government witness, law enforcement officer, or expert.
Examples:
Failing to disclose that a key eyewitness recanted testimony.
Concealing a forensic lab report that excludes the defendant as a DNA match.
Instructing police to withhold notes or recordings that contradict trial testimony.
Related Standards:
Brady v. Maryland, 373 U.S. 83 (1963): Requires disclosure of exculpatory evidence.
Giglio v. United States, 405 U.S. 150 (1972): Extends disclosure to impeachment material.
Kyles v. Whitley, 514 U.S. 419 (1995): Prosecutors are responsible for evidence in possession of the government, even if not personally aware.
ABA Model Rule 3.8(d): Prosecutors must timely disclose evidence that negates guilt or mitigates offense.
Consequences:
Suppression of witnesses or evidence can result in reversal of convictions, dismissal of charges, professional sanctions, contempt findings, and erosion of prosecutorial credibility.
