Discovery

Discovery in criminal cases is affected by the constitutional rights that protect the accused. Among the rights that play a role are the Fifth Amendment rights against compulsory self-incrimination and to due process and the Sixth Amendment right to effective assistance of counsel, all made applicable to the states through the Fourteenth Amendment. The right against compulsory self-incrimination means that discovery against the accused will at some point be restricted, which in turn means that criminal discovery cannot be fully a "two-way street." As interpreted by the Supreme Court during the last half of the century, the due process right means that the prosecution is constitutionally obligated to provide exculpatory information to the defense and to avoid use of false and perjured testimony. Effective assistance of counsel guarantees defendants critical aid in investigating and preparing a defense and occasionally provides arguments against usurpation of the defense counsels' preparation and obtaining defendants' communications.

The background for the debate about discovery in criminal cases is also affected by notions of the proper adversarial "balance," assessments of the state of that balance in the overall system, and predictions of the impact of discovery on it. Other important background factors are the presumption of innocence, the requirement of proof beyond a reasonable doubt, and the proposition that erroneous acquittals are more acceptable than are convictions of the innocent. Many of these propositions suggest that the discovery system should favor disclosure to the defense in service of protecting the innocent and in recognition of the prosecution's obligation to shoulder the entire burden of establishing guilt.

Supporting this asymmetry is the complementary argument that many aspects of the system tend to favor the prosecution. The prosecution typically has greater resources and can command an extensive investigative force in the form of police departments and other law enforcement resources. Evidence is usually gathered initially by the police, who have the power to search for and seize evidence under judicial authority and the ability to interrogate witnesses and the accused. The typically less adequately equipped defense attorney usually enters the case much later. Moreover, in some jurisdictions, the grand jury is an important investigatory tool that can compel testimony from witnesses and subpoena evidence.

The above characteristics often put the bulk of the evidence initially in the hands of the prosecution and suggest greater need by the defense to have access to prosecution-held information. In the initial stages of discovery reform, these features supported arguments to provide greater discovery to the defense. Justice William Brennan, one of the most effective advocates of this era, argued in an influential law review article in 1963 that defense discovery should be expanded to help turn the criminal trial from a sporting contest into a search for the truth. Such arguments were accepted for a time and to an extent. Thus, the initial expansion of discovery favored the defense almost entirely. Such discovery was designed to give the accused the basic facts to facilitate the rudiments of a defense. Ultimately, however, that one-sided argument could carry discovery only so far. It quickly encountered several counterarguments about peculiarities of criminal litigation that made unilaterally giving information to the defense highly problematic.

Critics often argued that because the stakes in criminal litigation for the accused are enormous and because many of those charged with crime are guilty and of questionable character, special dangers existed that the information disclosed would be misused. They contended that providing information to the defendant about the details of the prosecution case and its witnesses would likely lead to increased and more effective perjury and to intimidation of witnesses. Rejoinders can be made to many of the critics' arguments. However, at their base, most have some merit, and these concerns helped limit the further expansion of defense-oriented discovery. In addition, those opposing expanded defense discovery noted that in many jurisdictions the preliminary hearing allows the defense an extensive preview of the prosecution's case, although using this proceeding for discovery is sometimes considered an abuse. They also observed that the prosecution does not always enjoy a decided information advantage. Where defense counsel is expert and has adequate resources, independent investigation, aided by the defendant's knowledge of the facts, reduces or eliminates the prosecution's advantage, although most would acknowledge that only a relatively small group of defendants find themselves in this favorable situation.