The recent overturned conviction of a Tennessee woman illustrates the general purpose of discovery in criminal defense as well as the importance of compliance with the Brady rule. As reported recently in the New York Times Magazine, Noura Jackson was wrongfully convicted for her mother’s murder because the Shelby County, Tennessee prosecution team failed to turn over exculpatory evidence as required by law. As a result, she was imprisoned for nine years.
In Brady v. Maryland, the Supreme Court of the United States announced a rule, called the "Brady rule," which requires the prosecution in criminal cases to deliver exculpatory evidence to the defense. Exculpatory evidence is considered favorable to a defendant because it tends to show in a substantial and relevant way that the defendant may not be guilty of the crime or should not be punished for the crime charged. In the case of Noura Jackson, a note was withheld by prosecutors, which had the effect of undermining the credibility of a witness whose testimony was relied upon heavily by the prosecution.
The Tennessee criminal procedure rules outline the opportunity for the discovery of evidence in criminal cases by the state. According to the Tennessee Advisory Commission on the Rules of Practice and Procedure, the rules governing the state's disclosure of evidence do not limit discovery by defendants to only those methods specified. Rather, rules designed to preserve the due process rights of a defendant, such as the rule “as to the state’s duty to disclose exculpatory evidence,” which is governed by Brady v. Maryland, provide additional methods for a defendant to obtain evidence held by the prosecution. As “encouraged” by the Advisory Commission, all evidence not contemplated by Rule 16 should be voluntarily disclosed.
