Considerations for Disclosing Impeachment Information

Must a party to a case in a federal court disclose information that will be used solely for impeachment?  The quick response is no, but that isn’t the full answer.

Rule 26(a)(1)(a)(i) and (ii) require each party to affirmatively disclose certain information about witnesses and documents “unless the use would be solely for impeachment.”  To many, that is the end of the analysis.

However, this limitation is contained only in Rule 26(a)(1)’s affirmative disclosure limitations.  What if a discovery request is served seeking impeachment witnesses and documents?  This question arose in Derouin v. Kenneth L. Kellar Truck Line, Inc. where a video recording was at issue.[1]  “Defendants contend that they were under no obligation to provide the video recording to Plaintiffs and that the jury should have seen the recording because Defendants intended to use it ‘solely for impeachment.’”  The problem was there were numerous federal rulings concluding “a party must disclose impeachment evidence in response to a properly tailored discovery request.” 

A secondary question is whether the information is purely impeachment.  The defendant in that case argued the video was solely impeachment.  The court disagreed.  “The recording mostly, if not completely, contained substantive evidence to establish the truth of the matter to be determined by the jury, namely, the extent of [plaintiff]’s injuries.”  This requires both defining and distinguishing substantive evidence from impeachment evidence.  Derouin cited multiple sources to distinguish between the two, although it seems this is easier in theory than practice.

Substantive evidence is defined as “[e]vidence offered to help establish a fact in issue, as opposed to evidence directed to impeach or to support a witness’s credibility.”[2]  “Statements are useful as substantive evidence if they relate to a plaintiff’s prima facie case or a defendant’s affirmative defenses. Impeachment evidence is used to encourage the trier of fact to look critically at whether the evidence should be believed. In the ordinary case, impeachment evidence has no substantive purpose.”[3]  If evidence contains both substantive and impeachment evidence, it must be disclosed per Rule 26.[4]  However, when it must be disclosed may still be open to debate.


[1] No. C08-1049, 2010 U.S. Dist. LEXIS 156187 (W.D. Wash. Nov. 4, 2010).

[2] Black’s Law Dictionary (9th ed. 2009).

[3] Newsome v. Penske Truck Leasing Corp., 437 F. Supp. 2d 431, 435 (D. Md. 2006).

[4] See, e.g., Wilson v. AM General Corp., 167 F.3d 1114, 1118 (7th Cir. 1999); Klonoski v. Mahlab, 156 F.3d 255, 269-70 (1st Cir. 1998).