Legal Definitions - cumulative testimony

Cumulative testimony refers to evidence presented in court that merely repeats information already established by other witnesses or evidence, without introducing new facts, perspectives, or additional details. While some degree of repetition might be necessary for clarity or emphasis, courts often limit cumulative testimony to ensure efficiency, prevent undue delay, and avoid confusing the jury with redundant information.

• Example 1 (Eyewitness Accounts):

  In a civil lawsuit stemming from a traffic accident, the plaintiff calls three different eyewitnesses to testify about the collision. The first witness states that the defendant's car clearly ran a red light. The second witness then testifies, also stating that they saw the defendant's car run the red light. If the plaintiff then calls a third witness who provides the exact same account, simply confirming that the defendant ran the red light without adding any new details about the incident (such as speed, weather conditions, or other relevant observations), the third witness's testimony regarding the red light would be considered cumulative.

  Explanation: The core fact of the defendant running the red light has already been established by two prior witnesses. The third witness's testimony on this specific point adds no new information, making it redundant and thus cumulative.

• Example 2 (Documentary Evidence in a Contract Dispute):

  During a trial concerning a breach of contract, one party introduces several pieces of evidence to prove a specific clause existed. They present a signed contract, an email exchange confirming the clause, and meeting minutes where the clause was discussed and agreed upon. If they then attempt to introduce a fourth document, such as an internal company memo, that merely reiterates the existence and wording of the exact same clause without providing any new context, negotiation history, or impact analysis, the memo's content regarding that clause would be cumulative.

  Explanation: The existence and wording of the contract clause have already been thoroughly established through multiple forms of documentary evidence. The internal memo, by simply repeating this already proven fact, offers cumulative evidence on that specific point.

• Example 3 (Expert Witness Testimony):

  In a medical malpractice case, the plaintiff's attorney calls two different medical experts to testify about the defendant doctor's actions. The first expert provides extensive testimony detailing the standard of care for a particular surgical procedure and explains precisely how the defendant deviated from it, leading to the patient's injury. If the second expert then takes the stand and offers testimony that covers precisely the same ground, using identical reasoning and reaching the same conclusions about the standard of care and the defendant's deviation, without introducing any new diagnostic insights, alternative medical perspectives, or different aspects of the negligence, their testimony on those identical points would be cumulative.

  Explanation: The crucial expert opinion regarding the standard of care and its breach has already been fully articulated by the first expert. The second expert's testimony, by merely reiterating these exact same opinions and reasoning, does not introduce novel expert analysis or facts, making it cumulative.