OPINION
Andrew Leavy sought review of a court of appeals’ decision affirming the trial court’s order denying his motions for new trial. See Leavy v. Parsell, No. 1 CA-CV 95-0234, filed March 12, 1996 (Memorandum Decision). We granted review to determine whether the trial judge abused her discretion in failing to grant Leavy’s motions for new trial on grounds that defense counsel engaged in deliberate, serious misconduct. We have jurisdiction pursuant to Ariz. Const, art. 6, § 5(3), Ariz. R. Civ.App. P. 23, and A.R.S. § 12-120.24.
FACTS AND PROCEDURAL HISTORY
On May 23, 1992, Plaintiff Andrew Leavy (“Leavy”) and Defendant Gary Parsell (“Par-sell”) were involved in an automobile collision at the intersection of 90th Street and Cactus Road in Scottsdale. At the time of the accident, Parsell was driving a company vehicle and was performing his duties as an employee of Defendant Schendel Pest Control of Arizona. Leavy brought a personal injury action against Parsell and Schendel, seeking damages based on negligence and respondeat superior theories.
Prior to trial, Leavy filed motions in limine seeking among other things to preclude Par-sell from raising the seat belt defense and from introducing opinion testimony by Par-sell’s expert, Michael Broughton, regarding the credibility of certain accident witnesses, *71 especially Denise Ott-McLarty, on whose observatiоns Broughton relied in reaching his conclusions. The judge granted these motions, stating:
IT IS ORDERED Mr. Broughton cannot testify regarding the credibility of witnesses, but he can indicate which witnesses’ statements and testimony he relied on as the facts upon which his opinion is based. ‡ ‡ 9¡c $ $
IT IS ORDERED precluding the defendants from “raising” the seatbelt defense.
Leavy admitted prior to trial that a bottle of whiskey found near the accident site was his, but there was no evidence that Leavy used any alcohol prior to the accident or was impaired to any extent. We cannot tell from the record before us whether the judge ordered that the issue of alcohol use not be raised or whether counsel agreed not to raise it, but it is clear it was not an issue to be tried.
During his opening statement, defense counsel twice violated the judge’s orders by telling the jury that: (1) the emergency room records stated Leavy was “a probable unrestrained driver,” and (2) Ott-McLarty was described by an accident reconstruction expert as one of the best witnesses he had ever seen in sixteen years. Later the same day, during cross-examination of another witness, counsel asked if Leavy was wearing a seat belt when found in the vehicle immediately after the accident. Leavy’s counsel timely objected to the three improper comments and the objections were sustained. Believing the “bell had been rung” and not wishing to emphasize the matter, Leavy’s counsel did not request the judge to instruct the jury to disregard defense counsel’s stаtements. Instead, at the start of the second day of trial, Leavy moved for a mistrial based on defense counsel’s violation of the judge’s orders. The judge denied the motion because she could not recall the comments made during opening statement.
The parties presented conflicting evidence about how the accident occurred. Oddly, both drivers had been driving nearly identical, white, foreign-made, pickup trucks. According to Leavy, he was traveling westbound on Cactus Road, and Parsell was driving southbound on 90th Street and ran the stop sign, causing the accident. Parsell had retrogradе amnesia, but the version from the defense eye-witnesses, especially Ott-McLarty, was that Parsell was driving eastbound on Cactus Road and it was Leavy, traveling southbound on 90th Street, who ran the stop sign and caused the collision.
The jury returned a unanimous defense verdict. Leavy timely filed a motion for new triаl, arguing that defense counsel’s improper references to Leavy’s use or non-use of a seat belt and vouching for OtL-MeLarty’s credibility denied him a fair trial. At the hearing on the motion, the judge stated that defense counsel “clearly violated the motion in limini [sic],” and that he did so “with malice aforеthought.” According to Leavy’s counsel, jurors commented that they “saw the case as one that was 50/50” and “[ejxactly even.” The judge agreed with this assessment, adding, however, that she did not “see how anybody could get that extra 1 percent that’s necessary” to tip the balance in favor of onе party over the other.
Leavy then amended his' motion to include defense counsel’s repeated references to alcohol: by our count, counsel mentioned the whiskey bottle or Leavy’s possible use of alcohol prior to the accident on at least eleven occasions. The judge nevertheless denied both motions, noting in her order that there was no testimony about Leavy’s use of a seat belt because all objections to those questions were sustained. She agreed that defense counsel improperly asked many questions about Leavy’s use of alcohol and mentioned in his opening statement and during examination matters excluded by pretrial orders. She concluded, however, that
the misconduct violated the spirit and intent of the orders. The issue is whether the misconduct materially affected the plaintiffs rights.... The court is unable to find that the misconduct mаterially affected plaintiffs rights.
The court of appeals affirmed, holding that although defense counsel’s statements “cer *72 tainly had the potential to deprive Leavy of a fair trial,” the trial judge did not abuse her discretion in denying the motions for new trial. Leavy, mem. dec. at 9-10. We conclude the pоtential was realized and defense counsel’s misconduct deprived Leavy of a fair trial.
DISCUSSION
A. Grant v. Arizona Public Service Co.
The grant or denial of a motion for new trial on grounds of misconduct is a matter within the trial judge’s discretion. In exercising that discretion, the judge must decide whether the misconduct materially affected the rights of the aggrieved party.
Grant v. Arizona Public Service Co.,
The judge did not do so in this ease, denying the motions for new trial even though she recognized that the ease was very close. She must also have recognized that under the peculiar facts of this case, the credibility and accuracy of the witnesses for each side were the keys to the jury’s verdict. We are mindful that in Grant we said:
We are left here with a case in which the record could justify either a conclusion of prejudice or no prejudice____ Thus, ... if the trial court had granted a new trial, we would have no hesitancy in affirming. On the other hand, since the record also supports the contrary finding, we must affirm the order denying a new trial, unless some reason exists for departing from the usual rule.
Id.
at 456-57,
In Grant, a wrongful death case, during final argument plaintiffs counsel drew improper inferences from the admitted evidence. These comments were made primarily to support plaintiffs claim for punitive damages. Counsel also speculated on facts that were not only irrelevant but not in evidence, suggesting that the victim’s widow was not dating and had no plans to remarry. Counsel also peppered his closing remarks with improper personаl views and comments. We found that the trial judge had not erred in denying the motions for mistrial and for a new trial.
Various factors distinguish this case from
Grant.
First, the misconduct in this case was much more egregious than in
Grant.
Counsel deliberately and knowingly did what the judge expressly ordered him not to do. This was not a case of a lawyer getting carried away and injeсting improper issues or comments in final argument. Such misconduct occurs, improper though it may be. Instead, with what the judge accurately called “malice aforethought,” counsel deliberately and knowingly violated the judge’s orders on the motions in limine.
1
Second, one of the improper remarks was directly relevant to the issue of witness credibility, the essential issue in this case of diametrically conflicting stories. In
Grant,
on the other hand, the main purpose of counsel’s improper argument was to procure punitive damages. If the jury had awarded punitive damages, “we would have no hesitation in concluding that the misconduct probably influenced the jury.”
Id.
at 453,
In the present case,. defense counsel sought to tip the scales in his client’s favor by implying Leavy was negligent by failing to use his seat belt and by possessing or using alcohol; counsel also sought to bolster the credibility of a key defense witness on the issue of liability. We believe that because the evidence was quite evenly divided between the parties, defense counsel’s deliberate and knowing acts of misconduct *73 throughout the trial, some of which violated explicit, unambiguous court orders, may well have produced the very result sought.
How, then, should a trial judge resolve a close question of prejudice in deciding whether counsel’s acts probably influenced the jury?
B. Prejudice
If the law in civil cases requires that a litigant subjected to misconduct of the type presented in this case make an explicit showing of probable influenсe, then the rule is self-defeating. As we have recently recognized in other, similar contexts, it is impossible for a party to carry the burden of proving prejudice when the misconduct or error prevents the court from determining the exact extent of prejudice.
See Perez v. Community Hospital of Chandler,
We adopt that rule for this situation. Any other result would encourage deliberate, unethical conduct by giving lawyers carte blanche to violate professional standards and court orders with relative impunity. We preserve the rules that misconduct alone will not warrant a new trial and that the grant or denial of a new trial based on misconduct is within the judge’s discretion.
Grant,
The court of appeals believed that any possibility of prejudice was overcome because the trial judge sustained Leaves objections and instructed the jurors that counsel’s arguments and questions were not evidence. We disagree with this reasoning. Although the judge’s rulings on Leav/s objections prevented an extended discussion of the issues or answers to improper questions, the comments in opening statement and the later improper questions raised issues that were legally irrelevant but might have been considered important by the jurors. Further, we cannot adopt a rule that essentially allows lawyеrs freedom to knowingly and deliberately raise inadmissible and inflammatory matters during opening statements on the bare assumption that any harm will be cured by a later stock instruction that arguments and questions are not evidence. This result is neither desirable nor, we believe, pragmatically correct. Wе cannot presume that stock instructions will cure the introduction of excluded issues such as alcohol use, seat belt use, and one witness’ opinion of another.
C. Unprofessional Conduct
We make no finding of
unethical
conduct. Lawyers are “entitled to be heard before being branded as unethical practitioners.”
Grant,
We hope this opinion, like those in
State v. Killean,
Given the circumstances and facts set forth in this opinion and the trial judge’s conclusion, supported by ample evidence, that counsel’s conduct was both deliberate and knowing, we believe at least a prima facie case of unprofessional conduct exists. Our trial judges should not tolerate deliberate professional misconduct. At the hearing on the motion for new trial in this case, the judge said that if defense counsel ever again violated one of her orders, either in fact or in spirit, she would “take it out of his pocketbook.” But when faced with counsel’s deliberate, knowing misconduct, a trial judge should not wait until the next time. Prompt action may prevent misconduct the next time.
CONCLUSION
For the foregoing reasons, we vacate the court of appeals’ memorandum decision and the trial judge’s order and remand this case to the superior court with instructions to grant a new trial. The clerk of this court is also instructed to forward a copy of this opinion to the disciplinary department of the State Bar of Arizona.
Notes
. We believe the judge’s pretrial orders were quite clear, despite appellate counsel’s statement, during argument to this court, that they were ambiguous. We agree with the judge’s finding that trial counsel's conduct was knowing and intentional.