What Happens if New Evidence is Found During Trial?

Evidence is an important part of any trial, and there are statutory rules and guidelines which lay out the framework for everything from what can be used as evidence, how it can be collected, and how it can be used. There are also rules and guidelines for the various stages of litigation as they relate to evidence.

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There are important differences between civil cases and criminal cases when it comes to evidence and the various parties’ duties related to disclosures of newly discovered evidence.

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Generally speaking, evidence must be admissible, and it also must either be intended for use at trial by the holding party or have been requested by the opposing party during the discovery process. If neither party intends to use some particular bit of evidence during the course of the proceedings, and neither party has requested access to that evidence, there is no obligation on either side to deliver this evidence to each other or to the court. There is no reason to alert the other side of the court of evidence, which, regardless of its potential usefulness, no one has any intention of actually using it to bolster their claims.

Key Takeaways

• Evidence must be admissible, intended for trial use, or requested by the opposing party during discovery; otherwise, there is no obligation to disclose it.
• In civil cases, both parties have a continuing duty to disclose new evidence they intend to use or that has been requested, while in criminal cases, defendants generally have no duty to supply the prosecution with evidence against themselves.
• If new evidence arises during a trial, it must be disclosed promptly, and both civil and criminal cases have specific guidelines on how and when this must be done.

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Civil Cases

In civil cases, both parties to a trial have a duty to disclose evidence that they intend to use or which ahs been requested of them during the discovery process. In fact, there is a continuing duty to disclose, meaning that as the course of the case and trial progresses, if either party discovers new evidence which they intend to use or which has been previously requested of them.

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Under Amended Rule 415 on Regulation of Discovery, there is a continuing duty to disclose. This is defined in an order from the Illinois Supreme Court as follows:
“If, subsequent to compliance with these rules or orders pursuant thereto, a party discovers additional material or information which is subject to disclosure, he or she shall promptly notify the other party or his or her counsel of the existence of such additional material, and if the additional material or information is discovered during trial, the court shall also be notified.”

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An interesting thing to note here is that if the evidence in question is not subject to disclosure, in most cases, it does not necessarily need to be disclosed, but sometimes it may need to be disclosed anyway. That seems pretty obvious, but as with most things in the law, it does not always work out quite that way. If new information arises that can be dispositive of the case, but the existence was not known to the parties previously and was therefore not subject to disclosure, it can become subject to disclosure and will need to be turned over by the party intending to use it.

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Criminal Cases

In criminal cases, in general, defendants have no duty to supply the prosecution with any type of evidence that may exist against them, whether that is before trial or during trial. The prosecution has the duty of proof to show that the defendant is guilty of whatever criminal offense they are accused of, and therefore, the prosecution also has the duty to obtain the necessary evidence to prove the accusations. If, during a criminal trial, new evidence is discovered, if it is discovered by the defendant’s side, they will not have to disclose this newly discovered evidence to the prosecution or to the court – it is on the prosecution to discover this evidence themselves in order to use it as part of the trial.

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According to the Illinois Criminal Code, in a criminal case in which the prosecution intends to offer evidence of a prior conviction, for example, it must disclose the evidence at a reasonable time in advance of trial or during the trial if the court excuses pretrial notice on good cause shown. If new evidence is found after the discovery process has officially concluded, a party may submit a Motion for Leave to Amend their responses to discovery materials such as interrogatories.

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The defendant, on the other hand, must counter the prosecution’s legal attacks, and they will need to provide evidence to back up their defense. If something comes to light that may provide that defense, it would behoove the defendant to alert the court to its existence. But if something comes up that may actually be detrimental to the defendant, they have no obligation to alert the other party about it. There is no requirement for the defendant to do the prosecution’s job for them, and why would they want to further implicate themselves if the prosecution has overlooked something anyway?

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Sometimes, evidence is not even available before the trial has reached a certain point. This can happen when the parties are waiting for government records, for example, and they have not been furnished yet. It can also happen if the evidence does not yet exist but is anticipated to eventually exist, such as with claims of damage to a person’s earning potential due to defamation, leaving their professional reputation in tatters and no one wanting to hire them, for example.

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In Conclusion

Evidence may not be available or be known at the outset of litigation. If a matter goes to trial and new or newly available evidence comes up, it can be introduced into evidence, but there are certain caveats and rules that must be followed. As with most things in the law, the answer is “it depends.”