OPINION

IVEY, J.[fn*] [fn*] Assigned by the Chairperson of the Judicial Council.

Appellants, City of Bakersfield and one of its police officers, Burton Mahan, appeal from the judgment entered against them on December 9, 1983, as modified by the trial court's remittitur entered on February 7, 1984, and consented to by respondents on February 14, 1984.

The question presented is whether the trial court should have permitted appellants to call a veteran police officer to testify as an expert with regard to numerous defense contentions.

Appellants argue that the trial court erred in refusing to allow them to call their proposed expert to attempt to qualify him, and in excluding expert testimony — which would have tended to rehabilitate appellants' witnesses and which would have assisted the trier of fact — because the testimony embraced an ultimate issue in the case and because it would usurp the jury's function of weighing credibility.

We conclude that, while the trial court's stated grounds for disallowing the alleged expert testimony were partially improper, the judgment cannot be reversed due to the failure of appellants' offer of proof in the trial court.

FACTS

At trial, the defense sought to introduce the expert opinion testimony of Los Angeles Police Lieutenant Charles Higbie. During Higbie's 16-year career with the Los Angeles Police Department, he investigated approximately 1,000 officer-involved shootings. He had investigatory, supervisory and instructional experience in the field of police-related shootings, and for the past several years had been in charge of the officer-related shooting division of the Los Angeles Police Department. Higbie had never qualified in another court as an expert.

Appellants' offer of proof at trial consisted of representations set forth in their trial brief and comments by their counsel in two discussions between the court and counsel outside the presence of the jury.

In their trial brief, appellants stated that: ". . . Lt. HIGBIE's proposed testimony will include the following areas:

"1. Explanation of any inconsistencies in the testimony of officers MAHAN and MUDRYK.

"2. Statistical information relative to years in service of officers involved in shootings.

"3. Statistical information relative to the location of handguns on suspects involved in officer related shootings.

"4. Opinion testimony regarding the use of deadly force by officer MAHAN.

"5. Opinion testimony regarding the conduct of officer MUDRYK.

". . . . . . . . . . . . . . . . . . . . . . . . .

". . . LIEUTENANT HIGBIE will be asked questions regarding the use of force by officer MAHAN which will necessarily involve the ultimate issues of both negligence and self-defense."

In the course of the two extended discussions between the trial judge and counsel, counsel for appellants had the following comments: "Well, my expert has done nothing for 16 years but investigate officer related shootings. He is currently in charge of the division that does this. I'm not taking any police officer off the street to ask his opinion of self-defense. I'm taking someone who works just in that area. . . . [¶] If his Honor is inclined to not permit the testimony, I really do not want to waste a day and a half or so of travel time to get the person up here. . . . [¶] Many times, your Honor, in automobile accidents, you will have experts that give opinions on ultimate issues as to who caused the accident, what caused the accident. You know, it seems to me that I'm not off base asking a person who's done nothing but investigate police shootings whether or not this shooting is on policy. . . . [¶] [Going to ask him a hypothetical question] and also the fact that he has read the depositions, police reports, he's read everything that counsel and I have on this case. . . . [¶] [M]y expert, your Honor, has interviewed literally hundreds of police officers after shootings. He will testify that inconsistencies, especially of this nature, it's not unusual for this to happen, particularly when there's been no reenactment available the officer. He's been isolated. It is not at all unusual to have inconsistencies between several people that see an event. . . . [¶] . . . [H]e has certainly observed the stress that officers have at the time . . . statements [regarding shootings] are taken. . . . [¶] [Propose to call Higbie to testify that it is not uncommon in his investigations for officers to give inconsistent statements as to distances, who was present, how many shots were fired, and so forth and] [a]dditionally, I had hoped to ask him questions pertaining to ultimate issues in this case, to wit, self-defense."

The court denied defense counsel's request to admit Higbie's testimony on the grounds that: (1) Higbie's opinion that Mahan acted reasonably was "what the jury is going to be asked to decide, and that's really the sole question, I guess, before them;" (2) Higbie's opinion would have to be based on a hypothetical question containing inconsistent statements; (3) "the ultimate reason for having [Higbie testify that inconsistencies in officers' testimonies after shootings are not unusual] is so that the jury can dispel [ sic] the instruction that inconsistencies may be considered by them in judging . . . the credibility of a witness;" (4) the court did not think Higbie was an expert in the reasons — guilt, self-interest, bias, stress, trauma, etc. — that stories vary; (5) there would be insufficient foundation for any opinion from Higbie "showing that the officers were, in truth and in fact, telling the truth, that the reason why they gave inconsistent statements was because of the trauma of the circumstances"; (6) Higbie never had qualified as an expert in any other court; (7) the court "didn't think [Higbie] should be qualified, based on his experience"; and (8) the court did not think that an expert opinion on the "ultimate issue" as to whether Mahan "acted in self-defense or properly or within the law" would be proper "in this case, based on the showing that was made."

DISCUSSION I.

THE TRIAL COURT DID NOT REFUSE TO ALLOW APPELLANTS TO CALL THEIR PROPOSED EXPERT TO ATTEMPT TO QUALIFY HIM.

Defendants contend that the trial court "refused" to allow them to call Lieutenant Higbie in order to qualify him as an expert, that they were "summarily denied" this right, and that the refusal was an abuse of discretion.

The plain answer to these contentions is that they find no support in the record. There is nothing to indicate that the trial judge would have refused a request by appellants to have Higbie testify, out of the presence of the jury, with regard to his qualifications and to the matters which would be the subject of his expert testimony. The clear import of a number of the court's comments to counsel is just the opposite — that he would have welcomed an opportunity to hear from Higbie about his expertise and his proposed testimony.

In the course of the first colloquy between court and counsel — after the court had asked whether there were other cases in which opinion testimony with regard to self-defense had been allowed and whether Higbie had been qualified in other courts (the first question was not answered and the second was answered, "No") and after appellants' counsel had made the statement quoted above with regard to not wanting to bring the witness to Bakersfield, "[i]f his Honor is inclined [italics added] to not permit the testimony" — the court pointed out that it had received the trial brief only that morning and had not had a chance to read it entirely, that it appeared Higbie would give his opinion on the sole question before the jury, that the court did not understand how a proper hypothetical question could be phrased and that the court, unlike counsel, did not have an overall picture of what was involved in the case. The court then asked a number of questions that, while they may have been somewhat rhetorical, certainly should have suggested to counsel for appellants that he had to expand his offer of proof.

At the conclusion of the second discussion (which took place five days after the first), the court sustained respondents' "objection to this evidence," on the ground that it would not "be proper in this case, based on the showing that was made." (Italics added.) Counsel for appellants asked if the trial brief would be made part of the record and the court replied affirmatively. The court then asked, "Anything else before we adjourn?" to which appellants' counsel responded, "No, your Honor." At no time did appellants' counsel ask the court's permission to call Higbie in order to qualify him.

In People v. Rocco (1971) 21 Cal.App.3d 96 [ 98 Cal.Rptr. 365], a rape trial, defense counsel attempted to elicit opinion testimony of the police officer who investigated the complaint as to whether or not a rape in fact occurred. The prosecutor objected and his objection was sustained. On appeal defendant asserted that the court erred in rejecting the testimony without making an effort to determine the qualifications of the witness. The appellate court rejected this contention stating: "The burden was on appellant, if he wished to bring in opinion evidence, to establish the officer's qualifications as an expert, and the competency of opinion evidence on the matter in question. Appellant did not attempt to do so." ( Id., at p. 107.)

The trial court here had before it Higbie's qualifications, as set forth by appellants' counsel orally and in his trial brief. The court was not offered additional proof, in the form of Higbie's testimony or by any other means, before its ruling on Higbie's qualifications. The record does not demonstrate a "refusal" to allow appellants to call Higbie to attempt to qualify him.

II.

SOME OF THE COURT'S STATED GROUNDS FOR ITS DETERMINATIONS THAT HIGBIE WAS NOT A QUALIFIED EXPERT AND THAT HIS TESTIMONY WAS INADMISSIBLE WERE IMPROPER

The propriety of the court's refusal to qualify Higbie and to permit his testimony must be judged by the record before the court at the time. This is not to say that the reasons given by the trial court for finding Higbie unqualified, and his testimony inadmissible, were entirely proper.

A. The Court's Grounds for Determining Higbie Not Qualified.

(1) "The trial court is given considerable latitude in determining the qualifications of an expert and its ruling will not be disturbed on appeal unless a manifest abuse of discretion is shown." ( People v. Kelly (1976) 17 Cal.3d 24, 39 [ 130 Cal.Rptr. 144, 549 P.2d 1240].) (2) The court's ruling that Higbie was not qualified was based in part on the grounds that he had never been qualified previously as an expert and that the subject matter of his testimony was not appropriate in the case. Both of these grounds are erroneous, at least in part.

Evidence Code section 720 provides: "(a) A person is qualified to testify as an expert if he has special knowledge, skill, experience, training, or education sufficient to qualify him as an expert on the subject to which his testimony relates. Against the objection of a party, such special knowledge, skill, experience, training, or education must be shown before the witness may testify as an expert.

"(b) A witness' special knowledge, skill, experience, training, or education may be shown by any otherwise admissible evidence, including his own testimony."

A court should not exclude one from testifying because he has never testified before. If this were the practice of all courts, there would be no experts. On the other hand, the court should not disregard the factor entirely. When a proposed expert has not been qualified before, the court should take a closer look at his qualifications; however, primary reliance should not be placed on the fact that this will be his first time on the witness stand. To do so would deprive the court and the parties of valuable testimony of qualified experts. And, whether or not the subject matter of an expert's testimony will be admissible in the case has nothing to do with the expert's qualifications. The only relevance of the subject matter, when reviewing an alleged expert's qualifications, is to see if the person is "an expert on the subject to which his testimony relates." (Evid. Code, § 720)

To the extent the court utilized these two factors in determining that Higbie was not qualified, it abused its discretion. However, its findings that Higbie was not an expert in the reasons officers' stories vary, and that he was not qualified based on his experience, were proper exercises of the court's discretion "based on the showing that was made."

B. The Court's Grounds for Determining Higbie's Testimony Inadmissible.

People v. McDonald (1984) 37 Cal.3d 351 [ 208 Cal.Rptr. 236, 690 P.2d 709] was filed subsequent to the filing of the briefs in this case. It has an extensive discussion regarding expert testimony and, while it involves an area of expertise not relevant to the instant case, it provides us with guidance in the matter of expert testimony in general.

In McDonald, the defendant was charged with and found guilty of murder with the special circumstance that the murder was committed during a robbery of the victim. ( Id., at p. 355.) "The victim was shot during an argument on the corner of a busy intersection during rush hour. The entire event lasted only a few minutes. Eight eyewitnesses testified; four made positive identifications in court, three made tentative identifications (ranging from having doubts about the identification to feeling it was debatable whether they could identify the perpetrator) and one was positive McDonald was not the perpetrator. Of the four witnesses who made positive in-court identifications, three admitted their view was obscured by parked and moving cars, two admitted they were frightened at the time of the incident and one testified she deliberately kept her eyes averted from the perpetrator because of fear. None of the witnesses made a positive identification during the pretrial photographic lineup. No other evidence connecting McDonald to the crime was presented by the prosecution.

"McDonald presented six witnesses who testified he was in Saraland, Alabama, visiting relatives at the time of the shooting. Various aspects of the witnesses' testimony was corroborated by cards sent by McDonald and telephone records." ( People v. Jackson (1985) 164 Cal.App.3d 224, 243 [ 210 Cal.Rptr. 680].)

Defense counsel moved to admit the testimony of Dr. Shomer, an expert on the psychological factors that may affect the accuracy of eyewitness identification. ( People v. McDonald, supra, 37 Cal. 3d at p. 361.) Dr. Shomer was not going to offer an opinion that any particular witness was or was not mistaken in his or her identification. ( Id., at p. 362.) The People objected to the testimony because it would "`usurp the jury's function.'" ( Ibid.) The trial court agreed with the People. ( Id., at p. 363.)

The Supreme Court reversed. Noting the recent upsurge in impressive studies regarding eyewitness identifications ( id., at pp. 364-365), the court stated that the expert was not being called to testify to another's capacity but to inform the jury of factors that may impair the accuracy of eyewitness identification ( id., at p. 366), and that the phrase in Evidence Code section 801 limiting expert testimony to subjects "`sufficiently beyond common experience'" does not require that the jury be wholly ignorant of the subject matter of the opinion. ( Id., at p. 367.) "It will be excluded only when it would add nothing at all to the jury's common fund of information." ( Ibid.)

The court further stated that those cases which have rejected expert testimony to impeach a witness are not applicable in cases where the testimony does not attack the truth-telling ability of the witness ( id., at p. 370) and that the trial court's ruling that expert evidence on eyewitness identification will usurp the jury's function is "`a mere bit of empty rhetoric.'" ( Ibid.) ". . . The expert testimony in question does not seek to take over the jury's task of judging credibility: as explained above, it does not tell the jury that any particular witness is or is not truthful or accurate in his identification of the defendant. Rather, it informs the jury of certain factors that may affect such an identification in a typical case; and to the extent that it may refer to the particular circumstances of the identification before the jury, such testimony is limited to explaining the potential effects of those circumstances on the powers of observation and recollection of a typical eyewitness. The jurors retain both the power and the duty to judge the credibility and weight of all testimony in the case, as they are told by a standard instruction.

"Nor could such testimony in fact usurp the jury's function. As is true of all expert testimony, the jury remains free to reject it entirely after considering the expert's opinion, reasons, qualifications, and credibility. Indeed, the Penal Code commands (§ 1127b) that an instruction so informing the jury be given in any criminal trial in which expert opinion evidence is received.

"Finally, California has abandoned the `ultimate issue' rule in any event: `in this state we have followed the modern tendency and have refused to hold that expert opinion is inadmissible merely because it coincides with an ultimate issue of fact.' ( People v. Cole, (1956) supra, 47 Cal.2d 99, 105 [ 301 P.2d 854, 56 A.L.R.2d 1435], and cases cited.)" ( People v. McDonald, supra, 37 Cal.3d at pp. 370-371, fns. omitted.)

The court recognized that the trial court is left with a great deal of discretion when admitting expert testimony, but that this discretion is not absolute. ( Id., at p. 373.)

The court found that the expert was qualified; that the crucial factor in the case was eyewitness identification; that the evidence on this issue "was far from clear" ( id., at p. 375); and that the ruling excluding the expert testimony was unsupported by the record and by the law, and, therefore, constituted an abuse of discretion. ( Id., at p. 376.) Applying the Watson test, the court found the error reversible. "When an eyewitness identification of the defendant is a key element of the prosecution's case but is not substantially corroborated by evidence giving it independent reliability, and the defendant offers qualified expert testimony on specific psychological factors shown by the record that could have affected the accuracy of the identification but are not likely to be fully known to or understood by the jury, it will ordinarily be error to exclude that testimony." ( People v. McDonald, supra, 37 Cal.3d at p. 377, fn. omitted.)

Two other recent cases, People v. Bledsoe (1984) 36 Cal.3d 236 [ 203 Cal.Rptr. 450, 681 P.2d 291] and People v. Roscoe (1985) 168 Cal.App.3d 1093 [ 215 Cal.Rptr. 45], recognize two areas of expertise — rape trauma syndrome and child molest syndrome, respectively — more closely related to the subject matter of some of Higbie's proposed testimony.

In Bledsoe, the Supreme Court held that expert testimony that the complaining witness was suffering from rape trauma syndrome is not admissible to prove that she was raped; however: ". . . In a number of the cases in which the issue [of rape trauma syndrome] has arisen, the alleged rapist has suggested to the jury that some conduct of the victim after the incident — for example, a delay in reporting the sexual assault — is inconsistent with her claim of having been raped, and evidence on rape trauma syndrome has been introduced to rebut such an inference by providing the jury with recent findings of professional research on the subject of a victim's reaction to sexual assault. [Citation.] [delay in reporting assault]; [citation] [inconsistent post-incident statements by 14-year-old incest victim]; [citation] [brief return to scene of attack to retrieve belongings]; [citations.] As a number of decisions have recognized, in such a context expert testimony on rape trauma syndrome may play a particularly useful role by disabusing the jury of some widely held misconceptions about rape and rape victims, so that it may evaluate the evidence free of the constraints of popular myths." ( People v. Bledsoe, supra, at pp. 247-248.)

In Roscoe, this court held that the trial court erred in admitting a psychologist's testimony diagnosing the complaining witness as a molestation victim, but added that expert testimony "based on general literature or experience as to the reluctance of molest victims, as a class, to talk to investigators," was admissible "as bona fide rebuttal." ( People v. Roscoe, supra, at pp. 1100-1101.) ". . . [T]he expert testimony authorized by Bledsoe to permit rehabilitation of a complainant's credibility is limited to discussion of victims as a class, supported by references to literature and experience (such as an expert normally relies upon) and does not extend to discussion and diagnosis of the witness in the case at hand." ( Id., at p. 1100; fn. omitted.)

Thus — in light of McDonald, Bledsoe and Roscoe — the trial court's conclusions that Higbie's opinion was going to involve "the sole question" before the jury; that Higbie's testimony, that inconsistent statements after shootings are not unusual, would cause the jurors to ignore the instruction (CALJIC No. 2.20) that they could consider inconsistencies in judging the credibility of a witness; and that Higbie's opinion on whether Mahan "acted in self-defense or properly or within the law" involved the "ultimate issue" in the case, are at the very least questionable grounds for refusing to admit the testimony. On the other hand, the court's finding there was insufficient foundation for an opinion from Higbie that the officers were telling the truth and that the reason why they made inconsistent statements was "because of the trauma of the circumstances," was a proper exercise of the court's discretion, "based on the showing that was made."

It is possible Higbie could have demonstrated sufficient expertise to permit him to advise the jury as to the factors that may affect an officer's reaction when involved in a shooting, and to explain to the jury the potential effects of these factors on the officer's recollection. It is even possible that Higbie might have qualified to express an opinion on an "ultimate issue" in the case.

On the first point, the sole purpose of his testimony (like that of the experts in McDonald, Bledsoe and Roscoe) would be to explain the effects of a stress-causing event on one's perceptions and recollections. The jurors would retain both the power and the duty to weigh all the testimony and to judge the credibility of the witnesses, including Higbie.

The concern of the trial court that the expert would not know if a witness was falsifying his testimony willfully would also be a concern in eyewitness identifications and in statements of complainants in sex cases; and expert testimony is not excluded in these cases. Although an eyewitness or a rape victim might not appear to have as strong a motive to falsify as a police officer who has killed an unarmed civilian, this would be a factor to be weighed by the jury when it determines what value to give to the testimony.

Of course, the proffered testimony in the instant case was novel — the trial court characterized appellants' efforts as "trying to plow new ground in this case" — and was not backed by extensive scientific literature and scholarly studies as was the proffered testimony in McDonald and Bledsoe. But neither was it a subject which encompassed matters within a juror's common experience.

(3) The Kelly-Frye rule, "that evidence based on a new scientific method of proof is admissible only on a showing that the procedure has been generally accepted as reliable in the scientific community in which it developed" ( People v. McDonald, supra, at p. 372), is inapplicable in the instant case for the same reasons it was held inapplicable in McDonald. ". . . It is important to distinguish in this regard between expert testimony and scientific evidence. When a witness gives his personal opinion on the stand — even if he qualifies as an expert — the jurors may temper their acceptance of his testimony with a healthy skepticism born of their knowledge that all human beings are fallible. But the opposite may be true when the evidence is produced by a machine: like many laypersons, jurors tend to ascribe an inordinately high degree of certainty to proof derived from an apparently `scientific' mechanism, instrument, or procedure. Yet the aura of infallibility that often surrounds such evidence may well conceal the fact that it remains experimental and tentative. . . .

"Here, by contrast, no such methods are in issue. We have never applied the Kelly-Frye rule to expert medical testimony, even when the witness is a psychiatrist and the subject matter is as esoteric as the reconstitution of a past state of mind or the prediction of future dangerousness, or even the diagnosis of an unusual form of mental illness not listed in the diagnostic manual of the American Psychiatric Association. . . ." ( People v. McDonald, id., at pp. 372-373.)

With regard to Higbie's proposed expert opinion on whether Mahan acted in self-defense, the trial court's main concern appeared to be that the expert would be testifying to the "sole question" the jurors were to decide; that his opinion would "go to the ultimate issue, this ultimate issue is important and serious, and — well, I think it's the single most issue."

As the McDonald court noted, California abandoned long ago the "ultimate issue" rule and our law on this subject is codified in Evidence Code section 805, which declares: "Testimony in the form of an opinion that is otherwise admissible is not objectionable because it embraces the ultimate issue to be decided by the trier of fact."

It is clear from the entire record that the jurors were faced with a difficult decision. The facts presented a close question on the issues of negligence and self-defense. Respondents' counsel questioned Officers Mahan and Mudryk at length about inconsistencies in their various statements and testimony. He strongly emphasized these inconsistencies during his closing arguments, arguing that the officers gave testimony under oath that was untrue and hinting at a police coverup. Lieutenant Higbie's "expert testimony" might very well have provided a higher degree of credibility to the testimony of the officers, with the result that the jury might have reached a different verdict.

Whether the jurors also found the questions to be close is difficult to say from the record. The jurors commenced deliberations following lunch on December 7, 1983. At the end of the day (4:30 p.m.) they had not reached a verdict. They were excused for the evening and recommenced deliberations at 9:30 the following morning. They returned to the courtroom with their unanimous verdict at 4 p.m. that day.

III.

APPELLANTS FAILED TO MAKE AN ADEQUATE OFFER OF PROOF

(4) All of the foregoing notwithstanding, the fact that Higbie had investigated many hundreds of officer-involved shootings did not, in and of itself, make him an expert, nor did it make everything he might have had to say on the subject relevant. In addition, the fact that the trial court excluded Higbie's testimony for the wrong reasons does not require reversal by this court.

Evidence Code section 354 (reflecting the substance of Cal. Const., art. VI, § 13) provides in pertinent part: "A verdict . . . shall not be set aside, nor shall the judgment . . . based thereon be reversed, by reason of the erroneous exclusion of evidence unless the [appellate] court . . . is of the opinion that the error or errors complained of resulted in a miscarriage of justice and it appears of record that: [¶] (a) The substance, purpose, and relevance of the excluded evidence was made known to the court by . . . an offer of proof, or by any other means. . . ."

Evidence Code section 140 defines "`evidence'" to mean "testimony, writings, material objects, or other things presented to the senses. . . ."

As noted above, neither Higbie's failure to have testified previously nor appellants' attempt "to plow new ground in this case" mandated rejection of Higbie as an expert and of his testimony as potentially helpful to the jury; however, both were factors which the court could consider and together created a situation which compelled appellants to make a strong showing of Higbie's expertise and the relevancy of his testimony. This appellants failed to do.

In substance, appellants' offer of proof was that: (1) Higbie would testify that, in those shooting cases he had investigated, it was not uncommon for the officers involved to give inconsistent statements; and (2) Higbie would give his opinion that Mahan acted in self-defense. Thus, appellants advised the trial court of the substance of the facts they intended to prove instead of the evidence to prove the facts.

In United Sav. Loan Assn. v. Reeder Dev. Corp. (1976) 57 Cal.App.3d 282, the defendant asserted that the trial judge committed reversible error in excluding evidence which would have shown, among other things, knowledge by the plaintiff which would have made a notification provision of the parties' agreement inoperative.

"Reeder's offer of proof was to the effect that United had entered into written purchase and sale contracts with other buyers, both before and after the date of The Agreement between United and Reeder, which included the property subject to The Agreement; that these contracts were substantially the same as The Agreement between United and Reeder, with time-limit-condition-subsequent periods; that United followed a practice that if the buyer was doing engineering, going forward and attempting to put the package together, United would extend the deadline when the contract was to become absolute as long as the buyer was working in good faith to complete the transaction, and that at the end of the condition-subsequent time period, United voluntarily returned the deposited funds to the buyer and claimed no right to retain these funds.

"The trial court did not commit error in sustaining an irrelevancy objection to Reeder's offer of proof and excluding the proffered evidence. . . . Reeder's offer of proof was defective. The offer of proof did not make known to the trial court (1) the substance, (2) the purpose, and (3) the relevance of the proffered evidence that was excluded, as required by Evidence Code section 354, subdivision (a).

"The major defect was the failure of Reeder to set forth in its offer of proof the substance of the evidence that was being offered. . . . An offer of proof that sets forth the substance of facts to be proved does not comply with Evidence Code section 354, subdivision (a), since facts do not constitute evidence. The substance of evidence to be set forth in a valid offer of proof means the testimony of specific witnesses, writings, material objects, or other things presented to the senses, to be introduced to prove the existence or nonexistence of a fact in issue." ( Id., at pp. 293-294; fn. omitted.)

A proper offer of proof — setting forth the evidence to be presented through Higbie, the purpose for which such evidence was offered, its relevancy to the issues in the case, and the manner in which, and sources from which, Higbie acquired the information he would impart — would have afforded the trial judge a reliable basis on which to evaluate Higbie, his proffered testimony and whether the latter would assist the jury. With such a showing, the court could have exercised its discretion with a clear understanding of what was involved in allowing Higbie to testify. The best way to have done that was through the proposed witness.

This method, which was the one utilized by trial counsel in People v. McDonald, supra, 37 Cal.3d 351, and People v. Bledsoe, supra, 36 Cal.3d 236, would have given the trial court the opportunity to explore his concerns with Higbie present and under oath.

The responsibility for providing the court with the requisite offer of proof rests on the proponent of the proffered evidence and the obvious teaching of Evidence Code section 354 is that failure to meet that responsibility is fatal to an appeal based on exclusion of the evidence.

The fact that the trial court excluded Higbie's testimony for, to some extent, the wrong reasons does not avail appellants' cause. ( People v. Manriquez (1976) 59 Cal.App.3d 426 [ 130 Cal.Rptr. 585].) In Manriquez, the trial court permitted a juvenile codefendant to make a "`blanket assertion of the privilege against self-incrimination'" ( id., at p. 432) instead of requiring the witness to assert the privilege as to each question after having been sworn. The appellate court found that the trial court "thereby committed error. However, appellant made no offer of proof as to what the testimony of the witness would have been, and therefore the error was nonprejudicial. [Citations.]" ( Ibid.)

The judgment is affirmed.

Franson, Acting P.J., concurred.