When assessing under the Brady materiality standard whether "disclosure of the suppressed evidence to competent counsel would have made a different result reasonably probable," how should a court consider the impact of a key trial witness's assertion of the privilege against self-incrimination and refusal to testify when confronted with the suppressed exculpatory evidence?

When expert testimony relied on by the State in a criminal trial is later shown to be scientifically invalid, what is the appropriate standard to assess whether the State's use of scientifically invalid expert testimony was in violation of Due Process?

Does the conviction or execution of a person who is actually innocent of the crime violate the United States Constitution?

When assessing under the Brady materiality standard whether 'disclosure of the suppressed evidence to competent counsel would have made a different result reasonably probable,' how should a court consider the impact of a key trial witness's assertion of the privilege against self-incrimination and refusal to testify when confronted with the suppressed exculpatory evidence?