The job of a Massachusetts prosecutor is to seek the truth, not merely to pursue a conviction at all costs. However, in reality, there are social and professional pressures placed upon prosecutors to obtain convictions, and it is not unheard of for prosecutors to turn a blind eye to evidence that would tend to exonerate a defendant. Thus, in the 1963 case Brady v. Maryland, the United States Supreme Court held that a prosecutor in a criminal case must disclose all exculpatory evidence in its possession to the defense.
Over time, the Brady rule has expanded to include evidence that is relevant to “guilt or punishment,” as well as evidence that is in the control of other closely aligned government entities. Indeed, Massachusetts Rule of Criminal Procedure Rule 14 requires the disclosure of “any facts of an exculpatory nature.” However, determining exactly what is “exculpatory” can be difficult, especially if the defendant is not entitled to otherwise view the evidence.
One area that is frequently the subject of litigation is the personnel files of police officers. This evidence can be compelling if it shows that an officer involved in an arrest has been subject to disciplinary proceedings in the past. However, this evidence is not generally discoverable unless it is relevant. Thus, courts typically review the evidence in-camera, and then determine if it should be provided to the defense. A recent appellate decision in a Massachusetts gun case illustrates the difficulties defendants sometimes have in obtaining the personnel files of police officers.