Brady vs. Maryland and Giglio vs. United States

Brady vs. Maryland and Giglio vs. United States make it clear that prosecutors must disclose to the defense information which bears on the reliability or veracity of witnesses. U.S. Supreme Court decisions have enforced the "Brady Rule" to include evidence maintained in personnel files. That means that when a latent, tenprint fingerprint examiner or crime scene specialist has intentionally communicated either verbally or in writing a deceptive documented statement or message, the prosecutor must inform the defense. Intentional deceptive action in a formal setting, such as testifying in court, during an internal affairs investigation or false evidence that tends to implicate another in a criminal act, should result in termination or permanent removal from any position where the individual would be called upon to be a witness in any court action. The situation becomes less clear when the individual's actions cannot be determined to be intentional. An internal investigation might determine there was no evidence of criminal intent. An example might be an individual makes a wrong determination on a fingerprint identity, or crime scene tech. associates the wrong individual(s) with the scene based on the evidence collected. It is clear that the individual's history would be discoverable and impact the credibility of that individual testimony. What is not clear is the impact on a unit if the supervisor of the unit has the credibility issue, example the Mayfield case. If the testimony will come from another individual in the unit, does the fact that the supervisor may be perceived as having a credibility issue have any bearing on the case ?