There’s a reason that movies and television shows often focus on criminal trials: They make good drama. The stakes are high. There are clear actors, and it’s exciting to watch them grapple with the facts and look for the strategies that will best prove someone’s guilt or innocence.

But these shows often push the trials farther in the direction of drama than reality would allow. For example, show trials often feature surprise witnesses, who come in and condemn or exonerate the defendant with a key piece of testimony. However, the reality is that prosecutors must keep defendants and their lawyers informed of the witnesses and evidence they plan to use in trial.

What types of evidence do prosecutors need to share?

Discovery is the process through which prosecutors keep the defense informed of the witnesses and evidence they have found. Federal and state courts each have their own rules for discovery, but they often look much alike. That doesn’t mean the differences don’t matter. Good lawyers often use the discovery process to figure out their opponents’ likely arguments and prepare their counter-arguments.

According to the Offices of the United States Attorneys, federal prosecutors have an ongoing need to stay active with the discovery process, meaning several things:

• Discovery runs from the time the case begins until the trial.
• Prosecutors must share information about their potential witnesses and the types of testimony they might offer.
• Prosecutors must share the documents and other material evidence they intend to use.
• The law also says prosecutors must share any exculpatory evidence. This is evidence that might show the defendant’s innocence.

Similarly, Missouri rules also say that prosecutors need to share various types of evidence with the defense, including:

• Arrest reports and other reports related to the charges
• Any written or recorded statements made by the defendant
• The related portions of any grand jury proceedings
• Photographic or electronic surveillance related to the offense

There are different time limits for the discovery process, but prosecutors don’t always have to share their information right away. Sometimes they’ll share materials with the defense just a day or two ahead of the trial.

Why does the discovery process matter?

The discovery process is meant to add transparency. The goal is to help the courts reach fair and just decisions, informed by all the facts. It plays an important role in criminal cases and is a tool that skillful defense attorneys often use as they pursue justice for their clients.