Discovery

SIGNIFICANCE: An overriding goal of the criminal justice system is fairness and impartiality in all phases of trial processes, and the principle of discovery helps achieve that goal.

American courts operate under an adversarial system in which opposing legal teams attempt to further their versions of the truth while being overseen by neutral judges. This system is based on the premise that adversarial proceedings provide the best way to uncover the truth and determine the facts in a case. Another premise of the system is that the accused must be presumed innocent until proven guilty. It is thus the task of prosecutors to prove beyond a reasonable doubt that defendants have committed the crimes of which they are accused. To do so, prosecutors submit evidence and testimony in support of their case. In contrast, the role of defense attorneys in the adversary system is to contest the criminal allegations made against the defendants and dissuade the courts or juries from concluding that the defendants are guilty.

Purpose of Discovery

When preparing for trial, both prosecutors and defense attorneys need to examine all available evidence that has been collected by police investigators, results of any tests that have been conducted, and information about who is to be called to testify at the trials. American courts insist that both sides have equal opportunities to present complete cases, so that one side does not have an unfair advantage over the other. Discovery ensures that both sides have equal access to the same information.

Discovery involves both the formal and informal exchange of information between prosecutors and defense attorneys. The types of information considered “discoverable” vary from state to state. Items that are particularly likely to be considered discoverable include laboratory reports, fingerprint results, ballistic test results, witness statements, defendants’ confessions, psychiatric reports, and police reports.

The implementation of discovery tends to focus on the actions of prosecutors more than on defense attorneys because prosecutors have greater access to investigators (usually police officers), laboratory technicians, and advanced equipment for the analysis of evidence. If prosecutors were to restrict access to such information, it would jeopardize the right of defendants to fair trials. Defense attorneys therefore depend on strong discovery rules to secure their defendants’ rights. Allowing defense attorneys to learn what the prosecutors know or possess in the form of evidence may spare defense attorneys from the difficult task of attempting to force their clients to voluntarily disclose information that they are reluctant to admit.

In addition to the formal process of discovery, there is an informal process. Informal prosecutorial disclosure operates under the long-held theory that providing defense attorneys with advance viewings of prosecutors’ cases encourages guilty pleas and plea bargains. Because prosecutors believe that defendants tell their attorneys only part of the story, informal disclosure allows defense attorneys to be armed with the same information possessed by the prosecutors. The defense attorneys can use the evidence to confront their clients with more complete pictures of the events, which often leads both defendants and their attorneys to conclude that they would be better served by entering guilty pleas.

Informal and Reciprocal Disclosure

The process of discovery does not require that only prosecutors turn over their evidence to defense attorneys. Defense attorneys must reciprocate by disclosing all relevant materials in their possession. If trials are to be conducted fairly, both sides must start on a level playing field and be prevented from presenting surprise evidence.

As with many issues in state courts, reciprocal-disclosure requirements vary from state to state. Some jurisdictions require defense attorneys to file notices of alibi defense—claims that their clients were elsewhere when the crimes with which they are charged were committed—along with lists of witnesses to be called to support the alibis. Such pretrial notices allow prosecutors to investigate witnesses before they testify in court so they can counter the claims of the defendants. Some jurisdictions require similar pretrial disclosures from defense attorneys that an insanity defense will be entered or that expert witnesses will be called. Some states require defense attorneys to turn over to prosecutors the names, addresses, and statements of the witnesses they plan to call at trial.

The process of discovery is meant to ensure that the trial process results in a verdict based on all available evidence. The process achieves that goal when no side in a case is permitted to ambush the other with surprise evidence or witnesses because both sides have exchanged all relevant information.

Bibliography

Champion, Dean John, Richard D. Hartley, and Gary A. Rabe. Criminal Courts: Structure, Process, and Issues. 3rd ed. Upper Saddle River: Prentice, 2012. Print.

"Discovery Reform in New York Places Undue Burden on Prosecutors." Manhattan Institute, 19 Jan. 2023, manhattan.institute/article/new-report-discovery-reform-in-new-york-places-undue-burden-on-prosecutors. Accessed 14 Oct. 2025.

Hancock, Barry W., and Paul M. Sharp, eds. Criminal Justice in America: Theory, Practice, and Policy. 3rd ed. Upper Saddle River: Prentice, 2004. Print.

Neubauer, David W., and Henry F. Fradella. America’s Courts and the Criminal Justice System. 11th ed. Belmont: Wadsworth, 2014. Print.

Stolzenberg, Lisa, and Stewart J. D’Alessio, comps. Criminal Courts for the 21st Century. 3rd ed. Miami: Dept. of Criminal Justice, Florida Intl. U, 2010. Print.

Turner, Heidi. "What Is an E-Discovery Lawyer?" Clio, 26 July 2024, www.clio.com/blog/e-discovery-lawyer/. Accessed 14 Oct. 2025.