2. Disclosure of Exculpatory Evidence

The Due Process Clause of the Fourteenth Amendment requires prosecutors to disclose to the defense any exculpatory information they uncover. But the evidence does not always make its way into the defense counsel's hands. Sometimes this is because prosecutors willfully refuse to turn over the evidence despite its exculpatory nature. Take the case of Connick v. John Thompson spent eighteen years in the Louisiana State Penitentiary--most of them on death row--before his release in 2003. At his capital murder trial, Thompson opted not to testify in his own defense because he was previously convicted of armed robbery. The proof of his innocence of the armed robbery languished in the files of the New Orleans Crime Laboratory. One month before his scheduled execution, a defense investigator stumbled upon a lab report indicating that the blood evidence the prosecution presented at trial did not match Thompson's blood type. One assistant district attorney "intentionally suppressed [the] blood evidence," and then, shortly after being diagnosed with terminal cancer, confessed his wrongdoing to another assistant district attorney who did not reveal the secret until five years later. The Louisiana Supreme Court vacated both convictions. Upon his release, the Jefferson Parish District Attorney retried Thompson for capital murder. A jury acquitted him.

Why would prosecutors choose to not turn over exculpatory evidence? One possibility is that they are convinced that the defendant committed the crime despite the potentially exculpatory evidence, and they believe that the evidence would unduly harm the chance to convict a dangerous offender. Under this theory, whether to disclose potentially exculpatory evidence turns, in part, on the seriousness of the charges and the perceived strength of the defense case as discounted for revelation of the piece of evidence to the defense. Perceptions of the seriousness of the crime, in turn, depend in significant part on the how the prosecutor views the defendant. If the defendant is implicitly associated with hostility, criminality, or dangerousness, then implicit racial bias can influence the decision to disclose (or not) the ambiguous evidence by altering the perception of the defendant, which, in turn, alters the perception of the seriousness of the crime. Thus, prosecutors' decisions to comply with their Brady obligations also can be infected by implicit racial bias.