dissenting:
In my view, the trial judge’s decision to exclude certain evidence as a sanction for a discovery violation was within her discretion. Furthermore, if this evidence was offered solely to impeach T.B., it was of limited value in the context of all the other impeachment evidence. Thus, its exclusion would not constitute reversible error. I would therefore reverse the court of appeals’ decision, and accordingly, I respectfully dissent.
I.
The defendant was convicted of first degree sexual assault, a Class 3 felony, soliciting for prostitution, and harassment following a three day jury trial. The prosecution’s evidence reflects that the defendant picked up the victim, T.B., while she was hitchhiking during the early afternoon of August 14,1993 on Colfax Avenue. He took her to a secluded parking garage, struck her, forced her to perform oral sex, and then put her out of his car partially naked.
The defense asserted that T.B. was a prostitute who engaged in the charged acts on a consensual basis and who became angry with him because he refused to pay her the agreed-upon price for her services.
The charges were filed on August 18,1993, and the case went to trial in May of 1994. On December 23, 1993, defense counsel filed a Disclosure to Prosecution Pursuant to Crim. P. 16(11), in which he identified the nature of his defense as General Denial and *952Consent. He further noted that the witnesses whom he might call at trial in support of the defenses indicated were Paul Rado-vich, Walter Kraus, John Outlaw, and Ruth Barber, as well as any of the prosecution witnesses.
Trial began on May 25, 1994. On May 26, 1994, during a morning recess of the trial, the district attorney notified the court that she had just learned that the defendant had subpoenaed a police officer who was not identified in the discovery disclosures. The court and counsel addressed the issue outside the presence of the jury during the recess.
The record reflects that the police officer would have testified that he made contact with the victim, T.B., sitting in a man’s car on August 5th at 901 E. Colfax, close to the intersection of Ninth Street and Emerson Street. The man was arrested for check fraud. The officer would further have testified that the victim told him that she had ran out of gas. The contact between the officer and the victim was reflected on a police department contact card. In this context, a contact card is a record of a contact made between a police officer and someone who may have been suspected of prostitution. It is certainly arguable that the testimony and the contact card were intended to prompt the jury to reflect upon more than just the fact that the victim might have lied about having been at a particular location nine days prior to the charged incident.
Defense counsel argued that he intended to call the officer in order to impeach T.B.’s testimony, in particular her testimony during cross-examination that she was unfamiliar with the general area and with the specific intersection of Ninth and Emerson, and that she had not run out of gas on August 5th. He further argued that there was no duty under Rule 16 to disclose impeachment witnesses or evidence.
The trial court found that the evidence was rebuttal evidence in support of defendant’s general defenses; that defense counsel had known of the witness and the contact card for a period of time; that he had not disclosed the identity of the witness or the existence of the contact card to the prosecution or to the court; and that his motive for failing to disclose was trickery and deception.
The trial court precluded any testimony by the officer for two reasons: that defense counsel had, in bad faith, decided not to endorse the witness;1 and, the name of the witness had not been announced to the jurors during voir dire in order to permit any jurors who had knowledge of that witness to be excused. The court also prevented defense counsel from questioning T.B. about the contact, because the factual basis for such questioning stemmed from the officer’s excluded testimony.
The court of appeals assumed, without deciding, that the unendorsed witness should have been disclosed prior to trial under Crim. P. 16(II)(c). The majority opinion does not reach the question of whether defense counsel violated Rule 16 in its opinion.2 However, I believe the trial court was correct in classifying the unendorsed witness’ testimony as rebuttal evidence, which should have been disclosed by the defense prior to trial, thereby violating Rule 16.
II.
Rule 16 provides at Part 11(c): “Subject to constitutional limitations, the trial court may require that the prosecuting attorney be informed of the nature of any defense which defense counsel intends to use at trial and the names and addresses of persons whom defense counsel intends to call as witnesses in support thereof.” Crim. P. 16(II)(c).
*953The prosecution has even broader obligations to disclose witnesses and evidence to the defense under Rule 16. See Crim. P. 16(1). The intent of the Rule is to prevent trial by ambush: to permit counsel to be prepared, such that the jury can be presented with the evidence best calculated to lead to the truth. See People v. Castro, 854 P.2d 1262, 1264 (Colo.1993).
Here, the defense argues that the evidence at issue was impeachment evidence, and therefore the defense had no duty under Rule 16 to disclose it in advance. The trial court held that it was rebuttal evidence and subject to disclosure. There is indeed a distinction between impeachment evidence and rebuttal evidence, although that distinction is not outlined in Rule 16 itself, and the distinction is a slippery one.
The first precedent in Colorado is not precisely on point, but rather deals with the question in the context of an alibi defense. There, the court of appeals held that: “A distinction may be drawn between rebuttal testimony which refutes alibi evidence and impeachment testimony which does not contradict alibi evidence but does attack the credibility of defense witnesses on matters collateral to the alibi defense.” People v. Muniz, 622 P.2d 100, 103 (Colo.App.1980).
In People v. LeMasters, 666 P.2d 573 (Colo.App.1983), a dissenting opinion of the court of appeals stated:
Impeachment, in the evidentiary context, has been traditionally defined as the adducing of proof that a witness who has testified in a cause is unworthy of credit or belief. In this sense, impeachment evidence is limited to that which will directly and specifically disprove a witness’ statements and such evidence has been almost exclusively limited to prior inconsistent statements_ All other evidence tend-
ing to disprove a witness’ testimony is merely rebuttal evidence and must meet the same admissibility standards as any other evidence in the ease.
Id. at 579 (citations omitted).
Black’s Law Dictionary defines impeachment evidence as “proof that a witness is unworthy of belief’ and defines rebuttal evidence as “evidence given to explain, repel, counteract, or disprove facts given in evidence by the adverse party.” Black’s Law Dictionary 753, 1267 (6th ed.1990). Extrapolating from Muniz and LeMasters, with the assistance of the legal definitions, impeachment evidence is evidence that goes to the credibility of a witness. Rebuttal evidence goes to the heart of the case, reflecting upon the truth of facts upon which the other side relies..
As much as the distinction is difficult to generalize, it is even more difficult to apply with specificity in the heat of a trial. In the case before the court, it is my view that the trial court was justified in concluding that the testimony of the officer and the contact card were appropriately classified as rebuttal evidence that should have been disclosed by the defense prior to trial. Although defense counsel argued that the evidence went merely to the question of whether the victim was familiar with the area around Ninth and Emerson, it had prejudicial implications far beyond that. As the majority opinion points out, the evidence would tend to cast doubt on the victim’s representation to the effect that she ran out of gas on the day of the assault, and the jury could have conceivably inferred that she was engaged in an act of prostitution.
The testimony did not merely go to the victim’s credibility on a collateral issue, but rather to the heart of the defense. This witness was not a casual bystander who could testify that he had happened to see T.B. at Ninth and Emerson the prior week, an intersection with which she had said she was not completely familiar. Such evidence would have very limited impeachment value and might even have been irrelevant. Rather, the witness was a police officer who would testify that he had made contact with the victim in the vehicle of another man, where she said she was sitting because she had run out of gas. The jury would have been invited to speculate about the nature of the contact and about whether it related to prostitution.
Hence, in my view, the evidence was rebuttal evidence related to defendant’s defense and therefore subject to disclosure under Rule 16.
III.
The next question is whether the trial court impermissibly excluded the evidence in *954the face of the discovery violation. The majority concludes that the trial court failed to follow the standards of People v. Pronovost, 773 P.2d 555 (Colo.1989). I disagree.
A trial court possesses wide discretion in determining the proper sanction for discovery violations. See Castro, 854 P.2d at 1265; Pronovost, 773 P.2d at 558. The sanction must be “manifestly arbitrary, unreasonable, or unfair” in order to constitute an abuse of discretion. See Nagy v. District Court, 762 P.2d 158, 160-61 (Colo.1988).
The majority concludes that the trial court erred because the “record does not reflect consideration by the trial court of the Prono-vost factors.” Maj. op. at 949. I believe the record supports a finding in favor of the trial court’s ruling on each of the Pronovost factors, regardless of whether the trial court engaged in a formal, step-by-step analysis of each factor. Second, and more importantly, the trial court specifically found that defendant engaged in the type of willful misconduct that can warrant exclusion of evidence, even when all the Pronovost factors are not satisfied. See Taylor v. Illinois, 484 U.S. 400, 415, 108 S.Ct. 646, 98 L.Ed.2d 798 (1988); People v. Richards, 795 P.2d 1343, 1346 (Colo.App.1990).
In Taylor, the Supreme Court upheld the trial court’s exclusion of witnesses that the defendant had failed to disclose in a timely fashion. See Taylor, 484 U.S. at 418, 108 S.Ct. 646. The Court stated:
If [counsel’s explanation for the discovery violation] reveals that the omission was willful and motivated by a desire to obtain a tactical advantage that would minimize the effectiveness of cross-examination and the ability to adduce rebuttal evidence, it . would be entirely consistent with the purposes of the Compulsory Process Clause simply to exclude the witness’ testimony.
Id. at 415,108 S.Ct. 646.
The court of appeals correctly acknowledged in Richards that although exclusion is generally an inappropriate sanction, an exception exists in cases where defendant’s conduct amounts to “sandbagging.” Richards, 795 P.2d at 1346 (citing Taylor for the proposition that willful misconduct can justify exclusion).
None of the cases relied upon by the majority involve bad faith discovery violations. See People v. District Court, 793 P.2d 163, 168 (Colo.1990) (“The prosecutor did not willfully violate Rule 16, or otherwise act in bad faith.”); Pronovost, 773 P.2d at 559 (“It is conceded that the defendant’s failure ... was not willful or done in bad faith.”); see also Castro, 854 P.2d at 1265 (noting that “disclosure was not made in the present case because Castro did not believe that there was any information to disclose”); Richards, 795 P.2d at 1346 (finding “no indications of conduct sufficient to invoke the Taylor exception”); People v. Reger, 731 P.2d 752, 756 (Colo.App.1986) (noting that defendant “did not show any good cause excusing failure to comply” with discovery rules, but not finding bad faith or willful misconduct),3
When the trial court finds that counsel has acted in bad faith,4 the range of permissible sanctions broadens. See Taylor, 484 U.S. at 416-17, 108 S.Ct. 646 (“[T]he inference that [defendant] was deliberately seeking a tactical advantage is inescapable. Regardless of whether prejudice to the prosecution could have been avoided in this particular case, it is plain that the ease fits into the category of willful misconduct in which the severest sanction is appropriate.”).
Additionally, as noted above, even proceeding through the remaining Pronovost factors, there is ample support for the trial judge’s ruling. The prosecutor was quite obviously surprised by the proffered evidence. In their brief before this court, the People point out that another individual was also present at the time of the officer’s contact with the *955victim. The prosecutor could hardly be expected to locate and investigate this individual in the middle of trial in order to effectively respond to the proposed testimony. Further, no events occurred subsequent to the violation that might mitigate this prejudice. Finally, in my view, a less drastic alternative was not required.
The record also reflects the trial judge’s concern that this witness’ name had not been read to the jury during voir dire. There had been no opportunity to discover whether any of the jurors knew the witness, thereby increasing the possibility of taint and a subsequent mistrial. For this additional reason, it is rarely proper to allow a surprise witness.
IV.
Finally, I cannot possibly conclude that the omission of this particular impeachment evidence constituted reversible error. Defense counsel contends, and the majority’s reasoning relies upon, the fact that the evidence was to be offered solely for the purpose of impeaching T.B.
T.B.’s original testimony regarding her knowledge of the area at Ninth and Emerson was uncertain and equivocal. Countering her testimony with the assertion that she had been in the area before would hardly reveal a glaring fabrication. The testimony that she had run out of gas before on a particular day would have been more pointedly refuted. This too, however, still, only goes to a minor, collateral issue.
Most importantly, defense counsel in fact impeached T.B. numerous times with prior inconsistent statements made to investigators and with her testimony at the preliminary and motions hearings. Thus, the additional impeachment evidence, of limited value on its own, becomes particularly insignificant because it only represented a minimal part of the total opportunities to attack T.B.’s credibility.
If, on the other hand, defense counsel’s true purpose for introducing this evidence was to suggest to the jury that T.B. had engaged in prostitution in the past and thus had consented to the contact, this type of evidence was likely inadmissible under the rape shield statute. See § 18-3-407, 6 C.R.S. (1997). Accordingly, in this eircum-stance, even if defense counsel had properly endorsed the witness, the testimony still would have been inadmissible.
V.
I agree with the majority that truth-seeking is of paramount importance to our criminal justice system. I also note, however, that the discovery process and full disclosure are designed to protect the search for truth by preventing “trial by ambush.” In this case, the trial court was well within its discretion in ordering preclusion of the witness after a finding of bad faith.
I am authorized to state that VOLLACK, C.J., and MULLARKEY, J., join in this dissent.. The trial court referred to the fact that defense counsel had "anticipated the impeachment in his opening statement.” The record of the opening statement does not reflect a reference to the evidence. However, defense counsel admitted that he did bring it up in the course of voir dire. The record does not contain a transcription of voir dire, and therefore the exact comment made by defense counsel is not available to us.
. The majority states that "the defense’s failure to disclose might have been excused by the prosecution’s failure to produce the contact card...." Maj. op. at 949. Of course, the trial court is free to consider all relevant factors in determining how best to remedy a discovery violation. See People v. Pronovost, 773 P.2d 555, 558 (Colo. 1989). However, it is not appropriate for a party to defend against a discovery violation with a violation of its own.
. In Reger, cited by the court of appeals, the court of appeals found that the trial court did not abuse its discretion in precluding defendant's impaired mental condition defense, even though the lesser sanction of a continuance might have remedied the harm.
. During argument on the point outside the presence of the jury, the trial judge stated to defense counsel "[Y]ou deceived the Court, you deceived the prosecution.... It is clear to me ... that your motive for handling the situation this way was deception.”