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The Public Servant
The newsletter of the ISBA’s Standing Committee on Government Lawyers

September 2010, vol. 12, no. 1

The Affirmative Damage Rule

A few years ago, I was defending a psychiatric malpractice, wrongful death case before a jury. Opposing counsel subpoenaed one of my client’s co-workers as a non-hostile witness because the co-worker’s deposition testimony played right into the plaintiff’s theory of the case. But, as often happens, the co-worker testified at trial differently than at his deposition, which was a wonderful surprise to me. It was less wonderful for opposing counsel. He grabbed his copy of the deposition and attempted to impeach the co-worker. I immediately objected that he could not impeach his own witness. After a sidebar where we vehemently argued the issue to the amusement of the judge, my objection was overruled. The case proceeded to a verdict in favor of my client,1 but I was convinced my objection should have been sustained. I was wrong.

Supreme Court Rule 238(a) states, “The credibility of a witness may be attacked by any party, including the party calling the witness.”2 This Rule originally required the party calling the witness to prove they were surprised by the trial testimony before being able to impeach their own witness.3 Since 1982, the element of surprise has been abolished.4 Under current case law, such impeachment can occur when: (1) the trial testimony “affirmatively damages” the impeaching party;5 (2) the impeaching statement was “materially inconsistent” with the trial testimony;6 (3) the impeaching statement relates to a “material” matter;7 and (4) proper foundation is laid for the impeaching material.8 The foundation element is beyond the scope of this article because foundation requirements vary based on the type of inconsistent statement used for impeachment. Instead, we will focus on the first three elements of this test, generally called the Affirmative Damage Rule.

As government lawyers, we will most often come across the Affirmative Damage Rule in criminal matters involving an eyewitness who changes her testimony from a prior statement. But Supreme Court Rule 238 governs both civil and criminal matters, and there should be no difference in the application of this test between the two types of cases.9

1. The Trial Testimony Must “Affirmatively Damage” the Impeaching Party

Impeachment of your own witness through a prior inconsistent statement cannot occur unless you can sufficiently demonstrate that the trial testimony has damaged, rather than merely failed to support, your position.10 Asking a witness about a fact which would be favorable for you if true but receiving a negative reply does not result in affirmative damage.11 Instead, the testimony must give positive aid to your adversary’s case.12 The policy behind this is simple: no reasonable reason exists to impeach a witness who has not actually contradicted any of your evidence.13 The law does not allow us to use this impeachment method to present otherwise inadmissible hearsay to the jury.14 It is only when the witness' testimony is more damaging than his complete failure to testify would have been that impeachment can proceed.15

For example, in the malpractice case referenced at the opening of this article, the client’s co-worker testified at trial that she agreed with my client’s choice of medication. During the co-worker’s deposition, she stated that she disagreed with my client’s choice. Her trial testimony caused affirmative damage to my opponent’s case because the main thrust of his claims was the failure to properly medicate the plaintiff. In comparison, the co-worker’s trial testimony aided my client’s case because she asserted that my client’s medication orders were appropriate. Opposing counsel would have been in a better situation had he never called the co-worker to testify. Thus, the first element of the Affirmative Damage Rule was met.

2. The Trial Testimony is “Materially Inconsistent” with the Impeaching Statement

The second element requires that the impeaching statement be materially inconsistent with the trial testimony.16 The inconsistency does not require a direct contradiction, but a tendency to contradict the witness’ trial testimony.17 This determination is within the broad discretion of the trial judge.18

Applying the materially inconsistent element to our malpractice case, the co-worker stated at trial that she agreed with my client’s medication orders, while she testified to the exact opposite during her deposition. The trial testimony has more than just a tendency to contradict the deposition testimony. Therefore, this element of the Affirmative Damage Rule was met.

3. The Evidence Concerns a “Material Matter”

The third element focuses on whether the impeachment evidence is material to the case.19 The court looks to whether it is reasonably likely that the testimony would affect the outcome of the case.20 It is not enough for the evidence to merely help the offering party’s position.21 The evidence must be directly on point with the main issue(s) in contention.22 If the evidence speaks to a collateral matter, it does not meet this element.23

This element is the most flexible prong of the test because the materiality of an issue depends directly on the claims being brought before the court. In a criminal case, evidence is considered to be material when it tends to raise a reasonable doubt of the defendant's guilt.24 In civil cases, the materiality of evidence varies widely depending on the exact claims at issue.

In our malpractice example, the main claim against my client was that she placed the plaintiff on the wrong medication. The co-workers’ testimony was directly on point with this claim, and if it was left standing without impeachment, the jury could have used it to rule in my client’s favor. Thus, this evidence concerned a material matter, and the judge correctly let opposing counsel impeach this witness even though counsel had called her to the stand.

In summary, a party wishing to impeach a witness that it called must prove that the trial testimony damaged its case, the impeaching testimony is inconsistent with the prior statement, and the issue addressed by the testimony is material to the case. The normal foundation rules also apply when impeaching your own witness. The Affirmative Damage Rule gives us the ability to impeach witnesses that we call, thereby limiting the damage done to our case by our own witnesses. ■


Kevin Lovellette is an Assistant Illinois Attorney General. He is currently the supervisor of the Prisoner Litigation Unit in the Attorney General's Chicago Office. The opinions expressed in this article are his alone and do not necessarily reflect the opinions of the Office of the Illinois Attorney General.

Cody Cocanig is a third-year law student at Thomas M. Cooley Law School, and is a Law Clerk with the Illinois Attorney General’s Office.

1. Yes, I am bragging.

2. IL Sup Ct Rule 238(a).

3. People v. Hastings, 161 Ill.App.3d 714, 718 (1st Dist. 1987).

4. Id.

5. People v. Cruz, 162 Ill.2d 314, 359 (1994.)

6. Schiff v. Friberg, 331 Ill.App.3d 643, 656 (1st Dist. 2002).

7. Chapman v. Hubbard Woods Motors, Inc., 351 Ill.App.3d 99, 105 (1st Dist. 2004).

8. People v. Crowe, 327 Ill.App.3d 930, 938 (1st Dist. 2002).

9. Compare Hastings, supra, (criminal matter involving Affirmative Damage Rule) with Mueller v. Yellow Cab Co., 110 Ill. App.3d 504 (1st Dist. 1982)(civil matter involving same).

10. People v. Amato, 128 Ill.App.3d 985, 986-987 (3rd Dist. 1984).

11. Cruz, 162 Ill.2d 360.

12. Cruz, 162 Ill. 2d at 360 (citing Graham, Prior Inconsistent Statements-Impeachment and Substantive Admissibility: An Analysis of the Effect of Adopting the Proposed Illinois Rules of Evidence, 1978 U.Ill.L.F. 329, 372; see also M. Graham, Cleary & Graham’s Handbook of Illinois Evidence § 607.4m at 349 (5th ed. 1990)).

13. Amato, 128 Ill.App.3d 986 - 987.

14. Id.

15. People v. Weaver, 92 Ill.2d 545, 563-64 (1982).

16. Schiff, 331 Ill.App.3d 656.

17. Hastings, 161 Ill.App.3d 719.

18. Id.

19. People v. McLaurin, 184 Ill.2d 58, 89 (1998)

20. Id.

21. Id.

22. Id.

23. Id.

24. Id.