Many United States Supreme Court decisions have overturned criminal convictions for the reason that the government employed false evidence to obtain the conviction or failed to disclose relevant evidence important to the defense. In reversing federal or state judgments, the Court often has located direct proof of wrongdoing by the prosecutor. The notorious “bloody shorts” case is an example in point. There, the state introduced as evidence a pair of men’s “blood-stained” undershorts to achieve conviction of the accused. When the blood turned out to be red paint, the Supreme Court granted habeas corpus relief to the defendant because “[ilt was further established that counsel for the prosecution had known at the time of the trial that the shorts were stained with paint ... The prosecution deliberately misrepresented the truth.”
Judicial opinions in this area of the law have frequently emphasized the prosecutor’s historic duty not to convict but rather to do justice. Violations of this duty by the state’s prosecuting officer can create constitutional problems of verdict-rupturing magnitude: “It is as much his duty to refrain from improper methods calculated to produce a wrongful conviction as it is to use every legitimate means to bring about a just one.”
That deliberate evidence-suppressing conduct by the prosecutor voids a conviction is clear. But the problem becomes more difficult when the hiding of documents or witnesses is accomplished not by the prosecutor but by a lower-ranking minion of the state. What if a police officer discovers important evidence which is helpful to the defendant and fails to call it to the attention of either the prosecutor or the defense?
Consider a 1967 United States Court of Appeals proclamation on the subject:
So far as we have been able to ascertain, all the Supreme Court cases setting aside convictions for want of due process by reason of the reception of false testimony are based upon knowledge of the prosecutor that the testimony received is false or knowledge that material evidence has been suppressed. Such would appear to be a proper limitation of the rule.
Absent knowledge by the prosecutor himself, a police officer's misconduct in suppressing relevant evidence would be insufficient to invalidate the conviction. Other courts have displayed a decided reticence to overturn convictions without proof of complicity by the prosecutor in the wrongdoing. Such proof is frequently hard to come by, leaving open major issues in these cases: Does the conduct of a police officer in suppressing evidence constitute state action which deprives a conviction of its due process base, assuming such suppression is eventually discovered? In the false evidence cases, can a defendant who was condemned by perjured testimony successfully attack his conviction even though he lacks proof of governmental connivance in the perjury? In dealing with these issues this article explores the question of whether the Due Process Clause is addressed to the prosecutor alone, or applies as well to police and others who may traffic in suppressed or false evidence.
Ronald L. Carlson,
False or Suppressed Evidence: Why a Need for the Prosecutorial Tie?
Available at: https://digitalcommons.law.uga.edu/fac_artchop/377