July 30, 2021

Idaho follows the general rule that evidence of post-accident repairs or alterations, or “subsequent remedial measures,” to show antecedent negligence is inadmissible at trial.1 Under Idaho R. Evid. 407, the evidence is also inadmissible to show a defect in a product or design or a need for a warning or instruction. People usually think of this rule in the context of making repairs to a product or alterations to a product’s design after an injury occurs or posting warnings signs after an incident occurs.


The rule dates back more than 150 years, as demonstrated by an opinion from Sir Bramwell in 1869:

People do not furnish evidence against themselves simply by adopting a new plan in order to prevent the recurrence of an accident. I think that a proposition to the contrary would be barbarous. It would be (as I have often had occasion to tell juries) to hold that, because the world gets wiser as it gets older, therefore it was foolish before.2

Here in Idaho, the Supreme Court has voiced several reasons for the exclusion of evidence of subsequent remedial measures. The evidence is immaterial, it is irrelevant and unfairly penalizes an individual for post-incident conduct, there is a danger a jury will be improperly influenced by emotions, it distracts a jury from the main issues, it wastes time during trial presentations, and it could result in unfair surprise for the adverse party.3 The Supreme Court has also noted other jurisdictions exclude the evidence based on the social policy to encourage people to take action after an incident to further safety without fear that such action could later be used to show their negligence; however, the Court has not expressly embraced or rejected this policy rationale.4 Subsequent remedial measures that have been ruled inadmissible at trial in Idaho include installation of a caution sign for a bridge’s width5, changes in company policies6, business records showing remedial measures implemented7, and removal of a pharmaceutical drug from the market8; changes to appearance in sheen of floor9, changing location of handrail and posting signs10


While subsequent remedial measures are inadmissible to show negligence, a product or design defect, or a failure to warn, they are admissible for other purposes, “such as impeachment or – if disputed – proving ownership, control, or the feasibility of precautionary measures.”11


There have been two notable decisions by the Idaho Supreme Court where subsequent remedial measures were admitted. In 1956, in Zenier v. Spokane Int’l Railroad, the Supreme Court addressed the admission of evidence that a fence was constructed along a railroad tracks after the plaintiff’s livestock were hit by a passing train.12 The defendant failed to initially object to admission of the evidence and failed to move to strike the evidentiary testimony after it was elicited. After noting the failure to object at trial, the Supreme Court found the evidence was material because it showed the defendant’s recognition that it was bound to remedy gaps in the fence pursuant to I.C. § 62-406, which requires railroad companies to erect and maintain lawful fences along each side of its road. Later, in Otts v. Brough, evidence that a barricade was constructed over a large hole at a construction site after a person fell through the hole was admitted into evidence.13 The Supreme Court again found the evidence was not admitted to show antecedent negligence, which is prohibited, but it was instead admitted to show recognition of a defect the defendant was duty bound to remedy. The distinction drawn by the Supreme Court in the two cases certainly feels like semantics, but the cases seem to propose the evidence is admissible to prove a “duty” existed but not to show the duty was “breached.” It is unclear whether the Supreme Court would continue to approve admission of subsequent remedial measure to show acknowledgement of a duty by a defendant since the Zenier and Otts decisions were issued prior to adoption of the Idaho Rules of Evidence, which not only include Rule 407 but also include Rule 40314.


Watson v. Navistar Intern. Transp. Corp is another Idaho Supreme Court case that discusses the admissibility of subsequent remedial measures.15 In Watson, the trial court allowed evidence of subsequent design changes to an auger; specifically, a warnings signs and a cover. The evidence admitted was portions of a witness’ deposition transcript offered for impeachment purposes, i.e., to show the witness contradicted himself in part of his deposition concerning design changes. The defendant’s appealed, arguing the evidence was offered to show negligence under the guise of impeachment evidence. The Supreme Court found the trial judge did not abuse his discretion in admitting the evidence at trial because the trial judge was in the best position to assess the evidence at trial, the trial judge found the witness had in fact been impeached during his deposition, and the trial judge disallowed portions of the impeachment testimony based on Idaho R. Evid. 403. The Supreme Court also noted a limiting instruction could be used to aid a jury if there are concerns about a jury being misled.


  • Implementing new safety procedures after an accident occurs will not be used against you to prove negligence. Idaho R. of Evid. 407 can act as a security blanket to encourage individuals or companies to take additional steps to ensure safety.
  • However, it is important to consult an attorney before taking any subsequent remedial measures to discuss how they could impact you in other ways.
  • Other cases where evidence of subsequent remedial measures was allowed at trial in Idaho include testimony showing improper installation rather than defective design16 and impeachment with limiting jury instruction17.

Please contact a Gjording Fouser lawyer at 208.336.9777 if you would like any additional information about this topic or any other issues facing your company.

1 Leliefeld v. Johnson, 104 Idaho 357, 364, 659 P.2d 111, 118 (1983).

2 Hart v. Lancashire & Yorkshire Ry. Co., 21 L.T.R.(n.s.) 261, 263 (1869), quoted in 2 Wigmore, Evidence § 283, at 184 (Chadbourn rev. 1979).

3 Alsup v. Saratoga Hotel, 71 Idaho 229, 236-237 (1951) (“Changing conditions subsequent to the accident cannot be considered as proof of defendant’s negligence at some prior time. Where the question at issue is the liability of a defendant for alleged negligence because of the maintaining of a dangerous condition, the question at issue is what was the condition at the time of the accident and evidence of changed conditions subsequent to the accident, if intending to prove negligence at the time of the accident, are immaterial and present only collateral matters.”); accord Leliefeld, 104 Idaho at 364-65.

4 Leliefeld, 104 Idaho 357.

5 Id.

6 Jones v. Crawforth, 147 Idaho 11 (2009).

7 Adams v. U.S., CIV.03-0049E-BLW, 2009 WL 1269732 (D. Idaho May 6, 2009).

8 Cosgrove By and Through Winfree v. Merrell Dow Pharm., Inc., 117 Idaho 470 (1989).

9 Mann v. Safeway Stores, Inc., 95 Idaho 732 (1974).

10 Alsup, 71 Idaho 220.

11 Idaho R. Evidence 407.

12 78 Idaho 196, 203-04 (1956).

13 90 Idaho 124 (1965).

14 Rule 403 prohibits relevant evidence if the probative value is substantially outweighed by unfair prejudice, confusion, etc.

15 121 Idaho 643 (1992).

16 Cook v. Skyline Corp., 13 P.3d 857, 862 (Idaho 2000).

17 Hopkins v. Duo-Fast Corp., 123, Idaho 205 (Idaho 1993).