OPINION

LUCAS, C.J.

In this case we consider whether the trial court erred in rejecting five special jury instructions which defendant requested relating to the accuracy of eyewitness identifications. Defendant was convicted of armed robbery and related offenses in connection with a robbery at gunpoint by several masked men. The sole evidence against him at trial was eyewitness identification.

We conclude that the court correctly declined to give four of the five requested instructions. We also conclude that the court erred in failing to give an instruction listing the factors the jury could consider in evaluating eyewitness identifications, but we find the error was harmless.

I. FACTS

Defendant was charged with participating in the armed robbery of 11 employees of a wholesale beverage company in the company's warehouse and office building. His defenses were mistaken identification and alibi. The jury found him guilty of nine counts of armed robbery, two counts of attempted armed robbery, and one count each of assault with a deadly weapon and false imprisonment.

During the robbery, a group of men armed with handguns and wearing stocking masks burst into the company's warehouse, forced the employees to lie on the floor, and demanded their money. Some of the robbers then proceeded to the main office where they ordered the office employees to the floor and again demanded money. In addition, they forced one employee to open the company safe, and removed money from it. They also demanded jewelry from the victims. The robbers left the scene about 20 minutes after they arrived.

Three of the eleven employees present at the robbery identified defendant as one of the robbers. Stephanie Sung, the employee who opened the safe, was able to identify two of the robbers. As she went to the safe and opened it, she came "face to face" with one of them. She was able to observe this man's face through his black stocking mask, which, she testified, "wasn't very tight" and "didn't really smash his features." She also saw the face of a second robber as she returned from opening the safe. Later on the day of the robbery, she selected from a photo spread two photographs as resembling the robbers whose faces she had seen. One of these was defendant's photo, which Sung testified looked like the robber she saw as she opened the safe. She testified that at a lineup a week later she recognized defendant and was "75 percent sure" he was the robber she had seen at the safe, but she did not sign her lineup card, believing she had to be "a hundred percent sure" in order to sign it. During Sung's testimony, at the prosecutor's request, defendant put a stocking mask over his face. Based on this in-court demonstration, Sung positively identified defendant as the robber she had seen at the safe.

At another physical lineup about six weeks later, Sung identified the man pictured in the second photograph. She said the second man was the robber she saw when she returned from opening the safe.

Witness Erica Albertsen saw a man wearing a black stocking mask run toward her through the office door. The man grabbed her shoulders, lifted her up, and pushed her to the floor. She stated his mask did not hide his face, and she could see "very clearly" through the mask. She identified defendant as the robber she saw. She testified she had not seen a photo of defendant in the postrobbery photo spread, and that at the police lineup conducted later she was "amazed" to see defendant. At the lineup, she immediately recognized defendant as the robber she had seen. Further, she explained that her description of defendant at the preliminary hearing was from memory, given while defendant was hidden from her view.

Peter Marino also testified that defendant was one of the robbers, although he made a weaker identification. He picked defendant's photograph from the photo spread, saying, "this man [defendant] was in the warehouse that morning." At trial, he said that he could not specify which one of the group of robbers was defendant, but testified, "I believe [defendant] was in the robbery that day."

The eight other victims of the robbery testified that they were unable to say whether or not defendant was one of the robbers. The testimony of all the eyewitnesses will be discussed more fully where relevant below.

Defense counsel used a model to demonstrate the effect of the stocking masks. The model put on several masks, giving the jury an opportunity to observe how they distorted or otherwise affected the wearer's facial features. As noted, when the prosecutor had the defendant model a stocking mask, Stephanie Sung was able to identify him positively.

Defendant did not testify at trial. His wife testified that on the day of the robbery he was with her all day, sleeping most of the morning, and then decorating a bar for a birthday party. Defendant's sister-in-law testified that she had also been with defendant and his wife decorating for the party. Their testimony was uncorroborated and somewhat weak.

Defendant's sister-in-law stated on cross-examination that she had just found out the day she testified that the robbery took place June 8, that in the four months between that date and the trial she had not given any thought to the events of June 8, but that she remembered clearly that she had been decorating the bar and that defendant had been there all day. Defendant's wife stated she had not realized until a court hearing after defendant's arrest that he had been with her at the time of the robbery, and she had not mentioned this to anyone except her husband and her sister.

Defendant was tried together with a codefendant charged with participating in the same robbery. The case against the codefendant was also based on eyewitness identification testimony. The presentation of evidence took about eight days. The jury, after deliberating less than one day, found defendant guilty on all counts, but it was unable to reach a verdict as to the guilt of the codefendant. Defendant appealed on the sole ground that the trial court committed reversible error by refusing to give his five requested special instructions on eyewitness identification.

II. DISCUSSION A. Defendant's Special Instructions Nos. 1 and 4

(1) Requested instructions Nos. 1 and 4 state that the prosecutor has the burden of proof on the issue of identity. They essentially duplicate each other; more importantly, they also duplicate former CALJIC No. 2.91 (prosecutor's burden of proving beyond a reasonable doubt the accuracy of eyewitness identifications) which the court gave. ( Post, at p. 1149.) Defendant argues that his instruction No. 1 would additionally inform the jury that the identity of the criminal is an element of the crime; but this point is plainly implied by the statement in former CALJIC No. 2.91 that the prosecution has the burden of proving such identity beyond a reasonable doubt.

Defendant's special instruction No. 1 reads: "The identity of the defendant as the person who committed the crime is an element of every crime. The burden is on the State to prove beyond a reasonable doubt the accuracy of the identification of each of the defendants as a person who committed the offense. You are not permitted to find a defendant guilty of the crime charged against him based on the testimony of a witness identifying a defendant as the perpetrator of the crime unless you are satisfied beyond a reasonable doubt of the accuracy of that identification."
Defendant's special instruction No. 4 reads: "The burden is on the State to prove beyond a reasonable doubt that the defendant is the person who committed the offense with which he is charged. It is not necessary for the defendant to prove that another person may have committed the crime, nor is it the burden of the defendant to prove his innocence. You must be satisfied beyond a reasonable doubt of the accuracy of the identification of the defendant as the person who committed the offense before you may convict him. If, from the circumstances of the identification, you have a reasonable doubt whether defendant was the person who committed the offense, you must give the defendant the benefit of that doubt and find him not guilty."

All CALJIC instructions referred to are from the fourth edition (1979) unless otherwise noted.

Defendant also notes that instruction No. 4 would tell the jury he need not prove his innocence or another's guilt; but the court stated this rule in CALJIC No. 2.90, which defines the presumption of innocence and the prosecutor's general burden of proof beyond a reasonable doubt. Defendant's special instructions Nos. 1 and 4 are thus repetitious of instructions already given, and the trial court correctly refused them on this ground. ( People v. Martinez (1987) 191 Cal.App.3d 1372, 1378-1379 [ 237 Cal.Rptr. 219]; People v. McCowan (1978) 85 Cal.App.3d 675, 679-680 [ 149 Cal.Rptr. 611].)

B. Defendant's Special Instruction No. 2

(2a) Defendant's second proposed instruction lists certain specific items of evidence introduced at trial, and would advise the jury that it may "consider" such evidence in determining whether defendant is guilty beyond a reasonable doubt. The court refused to give this instruction because it is argumentative, i.e., it would invite the jury to draw inferences favorable to the defendant from specified items of evidence on a disputed question of fact, and therefore properly belongs not in instructions, but in the arguments of counsel to the jury.

Defendant's special instruction No. 2 reads: "In determining whether a reasonable doubt exists as to the guilt of Mr. Wright you may consider that:
"1. All of the robbers wore masks;
"2. The testimony of Inspector Cisneros regarding Peter Marino's comments at the time he viewed defendant Wright's photograph;
"3. The testimony of Inspector Cisneros regarding whether or not he showed Erica Albertsen defendant Wright's photograph, and whether or not she recognized that photograph;
"4. The testimony of Inspector Cisneros regarding Stephanie Sung's comments at the time she signed defendant Wright's photograph;
"5. People's Exhibit Number 20, a pink card with the name Stephanie Sung."

The court ruled correctly. In People v. McNamara (1892) 94 Cal. 509 [29 P. 953], a defendant charged with robbery was identified at trial by the victim. The court refused to give a proposed defense instruction telling the jury that in determining whether it had a reasonable doubt of the identity of the assailant it should "consider" specific evidence listed in the instruction, for example, that the victim was the sole witness to identify the defendant, that the victim was a stranger to the city, and the victim's "condition of sobriety or insobriety"; and that the defendant did not flee the city after the crime, but expressed his willingness to help recover the property and capture the robbers. ( Id., at pp. 513-514.) We held the instruction was properly rejected as argumentative. (3) We disapproved of "the common practice [of] select[ing] certain material facts, or those which are deemed to be material, and endeavoring to force the court to indicate an opinion favorable to the defendant as to the effect of such facts, by incorporating them into instructions containing a correct principle of law," and we explained, "An instruction should contain a principle of law applicable to the case, expressed in plain language, indicating no opinion of the court as to any fact in issue." ( Id., at p. 513; accord, People v. Hill (1946) 76 Cal.App.2d 330, 342 [ 173 P.2d 26]; see also People v. Slocum (1975) 52 Cal.App.3d 867, 893 [ 125 Cal.Rptr. 442].)

When the proposed instruction focuses exclusively or primarily on the testimony of one witness, it runs afoul of a well settled corollary of the foregoing rule, i.e., that it is "`improper for the court to single out a particular witness and to charge the jury how his evidence should be considered.'" ( People v. Lyons (1958) 50 Cal.2d 245, 271 [ 324 P.2d 556].) Instructions similar to defendant's No. 2 have been held improper on this ground as well. (See, e.g., People v. Smith (1977) 67 Cal.App.3d 45, 49-50 [ 136 Cal.Rptr. 387]; People v. Whittaker (1974) 41 Cal.App.3d 303, 308 [ 115 Cal.Rptr. 845] .)

The foregoing rule was not undermined by the 1934 constitutional amendment permitting a trial court to "make such comment on the evidence and the testimony and credibility of any witness as in its opinion is necessary for the proper determination of the cause." (Cal. Const., art. VI, former § 19, now § 10.) (2b) We deal here with an instruction, not a judicial comment; although such a comment may address matters of fact, an instruction may not. (4a) "[I]t is not a matter of law for the judge to say that certain evidence might give rise to a reasonable doubt as to the affirmative of an issue required to be proven by the prosecution. That is a comment on the evidence and any such comment should be identified as such." ( People v. Castellano (1978) 79 Cal.App.3d 844, 858 [ 145 Cal.Rptr. 264].) (2c) Moreover, even if defendant had characterized his request as a proposed judicial comment on the evidence rather than an instruction, it would still have been improper. (4b) "Judicial comment should be temperate rather than argumentative and the trial court must avoid engaging in partisan advocacy." ( People v. Cook (1983) 33 Cal.3d 400, 408 [ 189 Cal.Rptr. 159, 658 P.2d 86].) Judicial comment "should, in the interests of justice, not be limited within an area selected by the defendant, nor given in language of his choosing." ( Castellano, supra, 79 Cal.App.3d at p. 858.)

Penal Code section 1127 clearly draws the distinction between the functions of the comment and the instruction. It reiterates the court's constitutional power to "comment on the evidence," but goes on to provide with regard to instructions that "Either party may present to the court any written charge on the law, but not with respect to matters of fact. . . ." (Italics added.)

2d Defendant's instruction No. 2 follows the form of a requested instruction quoted in People v. Sears (1970) 2 Cal.3d 180, 189-190 [ 84 Cal.Rptr. 711, 465 P.2d 847]. The Sears instruction would have told the jury it could consider evidence such as "[t]he lack of motive" and "defendant's prior consumption of alcoholic beverage" in determining whether there was a reasonable doubt as to the existence of premeditation and deliberation. ( Id., at p. 189.) We held in Sears that the defendant was entitled to an instruction relating certain evidence brought out at trial to the issue of premeditation and deliberation. But the quoted instruction was not intended to serve as a model; indeed, we warned in Sears that the instruction is "defective in form in some respects" and emphasized that on retrial the court should give " appropriate instructions, if they are requested." ( Id., at p. 190, italics added; see People v. Whittaker, supra, 41 Cal.App.3d at p. 308.)

In addition, defendant mistakenly argues that Sears supports his position by its statement that a defendant "has a right to an instruction that directs attention to evidence from a consideration of which a reasonable doubt of his guilt could be engendered. ( People v. Granados [(1957)] 49 Cal.2d 490, 496 [ 319 P.2d 346].)" (2 Cal.3d at p. 190.) This statement is taken out of context. Neither it, nor the broader observation in Sears that "[a] defendant is entitled to an instruction relating particular facts to any legal issue" ( ibid.), abrogated sub silentio the well settled rule against argumentative instructions on a disputed question of fact. "`None of the cases cited in Sears says, and Sears itself does not say, that upon request the judge must direct the attention of the jury to specific testimony and tell the jury it may look to that testimony for the purpose of forming a reasonable doubt on an issue.'" ( Castellano, supra, 79 Cal.App.3d at p. 858.)

As appears from an analysis of the full Sears opinion ( supra, 2 Cal.3d 180), and from the sources it relied on, the language quoted by defendant refers only to a defendant's right to an instruction that "pinpoint[s] the theory of the defense." ( Granados, supra, 49 Cal.2d at p. 496.) In a proper instruction, "[w]hat is pinpointed is not specific evidence as such, but the theory of the defendant's case." ( People v. Adrian (1982) 135 Cal.App.3d 335, 338 [ 185 Cal.Rptr. 506], original italics.)

The difference between an instruction that pinpoints the crux of the defense and one that improperly implies certain conclusions from specified evidence is illustrated by People v. Wilson (1929) 100 Cal.App. 428 [ 280 P. 169], a case relied on in Sears. The defendant in Wilson, charged with robbery, put on an alibi defense. The court instructed generally that the prosecution must prove every material fact beyond a reasonable doubt, and defined reasonable doubt by the statutory instruction set out in Penal Code section 1096 (CALJIC No. 2.90). The defendant specially requested additional instructions that explained the alibi defense, relating it to the prosecution's burden of proof, and advising the jury that if it believed the defendant was not present when the crime was committed, he should be acquitted. The court refused these instructions.

The language of Sears that defendant invokes (regarding an instruction referring to "evidence in the case from which reasonable doubt of the guilt of the defendant may be inferred") first appeared in Justice Houser's opinion in Wilson. (100 Cal. App. at p. 432.) We therefore look to the facts and holding of Wilson for a better understanding of this language.

On appeal from his conviction, the defendant in Wilson relied on earlier cases holding such alibi instructions proper. The People argued that because of the then-recent enactment of Penal Code section 1096a, rejection of the alibi instruction was not error. Section 1096a declares that if the court gives the section 1096 statutory instruction on reasonable doubt, "no further instruction . . . defining reasonable doubt need be given." The Court of Appeal reversed the conviction, distinguishing between instructions merely "defining" reasonable doubt and those "covering a defense as shown by the evidence in the case from which reasonable doubt of the guilt of the defendant may be inferred." ( Id., at p. 432, italics added.) The defendant's requested instruction was in the latter category, for it pinpointed the theory of the defense, namely alibi, and charged the jury on how to relate the evidence of that defense to the prosecution's general burden of proving guilt beyond a reasonable doubt. The alibi instruction upheld in Wilson was subsequently formalized as CALJIC No. 4.50, and was given in the present case. ( Post, at p. 1150.)

A similar evolution occurred with respect to a special instruction on the mistaken identification defense. In People v. Gomez (1972) 24 Cal.App.3d 486 [ 100 Cal.Rptr. 896], the defense was both alibi and mistaken identification. The trial court gave the alibi instruction of CALJIC No. 4.50, but refused to give a requested instruction explaining that the prosecution has the burden of proving not only that the offense was committed but that it was the defendant who committed it; that the jury must be satisfied beyond a reasonable doubt of the accuracy of the identification of the defendant before it may convict; and that if the circumstances of the identification are not convincing beyond a reasonable doubt, the jury must find the defendant not guilty. The court rejected this identification instruction on the ground the issue was covered by the general statutory instruction on proof beyond a reasonable doubt as set out in Penal Code section 1096 and CALJIC No. 2.90. The Court of Appeal held this refusal error, relying on the Wilson-Sears language quoted ante at page 1137. ( Id., at p. 490.)

The Gomez instruction on the burden of proof of identification was formalized as CALJIC No. 2.91. In the present case the court gave the Gomez instruction, thus pinpointing the defense theory of mistaken identification and charging the jury on how to relate the evidence of that defense to the prosecution's general burden of proving guilt beyond a reasonable doubt. (See post, at p. 1149.) Defendant's further requested instruction No. 2 was properly rejected as argumentative. Numerous decisions have held similar instructions properly refused. (E.g., People v. Kaiser (1980) 113 Cal.App.3d 754, 764-766 [ 170 Cal.Rptr. 62]; People v. Guy (1980) 107 Cal.App.3d 593, 602-604 [ 165 Cal.Rptr. 463]; People v. Watson (1979) 89 Cal.App.3d 376, 385-387 [ 152 Cal.Rptr. 471]; People v. Smith, supra, 67 Cal.App.3d at pp. 48-49; People v. Whittaker, supra, 41 Cal.App.3d at pp. 307-309.)

C. The Eyewitness Identification "Factors" Instruction 1. Failure to Give the Requested Instruction Was Error

(5a) Defendant's requested instruction No. 3 lists certain factors, supported by the evidence in the case, that are relevant to the jury's evaluation of eyewitness identifications. It focuses on three main areas: 1) the witness's ability to observe the person being identified at the time of the crime; 2) the reliability of the witness's subsequent identification of the defendant; and 3) inconsistent or erroneous identifications the witness may have made before trial. We hold it was error, in this case, to reject the requested instruction.

The requested instruction reads: "Identification testimony is an expression of belief or impression by the witness. Its value depends on the opportunity the witness had to observe the offender at the time of the offense and to make a reliable identification later.
"In evaluating the identification testimony of a witness, you should consider the following:
"1. The circumstances under which the original observation was made, including: the witness' ability to observe when considering lighting and obstructions, if any; the length of time the witness had to make the original observation; whether or not the witness was under stress at the time of the observation; and any other circumstances which you find from the evidence;
"2. The circumstances of the subsequent identification, including whether or not the identification was the product of the witness' own independent recollection, and the strength of the identification; and
"3. Any occasions on which the witness failed to make an identification of the defendant or made an identification inconsistent with his or her identification at trial."

Defendant's special instruction derives from a well-known model instruction originally promulgated in United States v. Telfaire (1972) 152 App.D.C. 146 [ 469 F.2d 552, 558-559]. The first California decision to discuss the Telfaire instruction was People v. Guzman (1975) 47 Cal.App.3d 380, 386-387 [ 121 Cal.Rptr. 69]. Guzman held that although the Telfaire instruction was probably "too long and argumentative" as written, it "at least presents the basic problem and could have been modified to eliminate the faults contained." ( Id., at p. 386.)

The Telfaire instruction, listing factors the jury should consider in appraising eyewitness identification testimony, has been approved in most federal circuits, and in the state courts of Kansas, Massachusetts, New York, Utah, and West Virginia; in other states it has met with resistance on various grounds. Some of the out-of-state cases are analyzed in Note, Eyewitness Identification Testimony and the Need for Cautionary Jury Instructions in Criminal Cases (1983) 60 Wn. U.L.Q. 1387, 1402-1419. (See also Annot. (1983) 23 A.L.R.4th 1089.) The need for a Telfaire type instruction in appropriate cases is discussed in the cited note at pages 1419-1435. (See also Comment, Helping the Jury Evaluate Eyewitness Testimony: The Need for Additional Safeguards (1984) 12 Am.J.Crim.L. 189, 212-224; Comment, Seeing is Believing? The Need for Cautionary Jury Instructions on the Unreliability of Eyewitness Identification Testimony (1983) 11 San Fernando Val.L.Rev. 95, 114-122.)

Footnote 1 of Guzman quotes four requested instructions; the first of those four, hereinafter called the Telfaire-Guzman instruction, essentially followed the language of the Telfaire model instruction. We criticized Guzman on other grounds in People v. McDonald (1984) 37 Cal.3d 351, 371, footnote 18 [ 208 Cal.Rptr. 236, 690 P.2d 709, 46 ALR4th 1011].

After Guzman, various courts held that a refusal to give a requested Telfaire-Guzman instruction either was not error, or was harmless because the trial court gave general instructions on eyewitness identifications (usually CALJIC Nos. 2.20 and 2.91). (E.g., People v. Boothe (1977) 65 Cal.App.3d 685, 689-690 [ 135 Cal.Rptr. 570] [rejection of instruction harmless under Guzman]; People v. Hurley (1979) 95 Cal.App.3d 895, 900-901 [ 157 Cal.Rptr. 364] [no error in rejecting a lengthy requested instruction; Telfaire-Guzman instruction or other detailed instruction not required].) We first discussed the Telfaire-Guzman instruction in People v. Hall (1980) 28 Cal.3d 143 [ 167 Cal.Rptr. 844, 616 P.2d 826]. There, the trial court refused to give a proposed instruction identical to the instruction requested in Guzman. ( Id., at pp. 158-159.) Some of the factors highlighted in the requested instruction were inapplicable to the evidence in the case, so it was not error to refuse to give the instruction as written. We held, however, that the court's refusal to delete the inappropriate factors from the instruction and give a properly tailored instruction was error. ( Id., at p. 159.) We found the error harmless because the court gave CALJIC Nos. 2.20 and 2.91, but declared, "In the future, the trial courts should consider and give appropriate instructions involving reasonable doubt and eyewitness identification." ( Id., at pp. 159-160.) We stated, "it is error to refuse to give an instruction requested by a defendant which `directs attention to evidence from . . . which a reasonable doubt of guilt could be engendered.' ( People v. Sears [ supra] 2 Cal.3d 180, 190 [ 84 Cal.Rptr. 711, 465 P.2d 847].) This applies with equal force to a refusal to give a requested instruction which deals with identification in the context of reasonable doubt." ( Id., at p. 159.)

Following Hall, supra, 28 Cal.3d 143, some courts continued to hold that general instructions on eyewitness identification rendered Guzman-type instructions superfluous. (E.g., People v. Sequeira (1981) 126 Cal.App.3d 1, 17-18 [ 179 Cal.Rptr. 249] .) Beginning with People v. West (1983) 139 Cal.App.3d 606 [ 189 Cal.Rptr. 36], however, the Courts of Appeal have generally held it error, in appropriate cases, to refuse an instruction listing the factors the jury may consider in evaluating eyewitness identification testimony. (E.g., People v. Palmer (1984) 154 Cal.App.3d 79, 89 [ 203 Cal.Rptr. 474]; People v. Coates (1984) 152 Cal.App.3d 665, 670-671 [ 199 Cal.Rptr. 675]; People v. Brown (1984) 152 Cal.App.3d 674, 678 [ 199 Cal.Rptr. 680].) In People v. Yeats (1984) 150 Cal.App.3d 983, the court reviewed Guzman, Hall, and West, and concluded that "an unbroken string of authorities requires the giving of factually appropriate pinpoint jury instructions correlating the issues of identity and reasonable doubt." ( Id., at p. 990.)

In People v. McDonald, supra, 37 Cal.3d 351, we addressed the admissibility of expert testimony regarding the psychological factors that can affect the accuracy of eyewitness identifications. While we noted that "the decision to admit or exclude expert testimony on psychological factors affecting eyewitness identification remains primarily a matter within the trial court's discretion" (37 Cal.3d at p. 377), we held that on the facts of that case the exclusion of such expert testimony was a prejudicial abuse of discretion. ( Id., at p. 376.) We also noted a defendant may be entitled to a special instruction on these psychological factors, but observed that "the proper wording of such an instruction [listing factors affecting the accuracy of eyewitness identifications] remains unsettled." ( Id., at p. 377, fn. 24.) We refrained from expressing any view on that question. ( Ibid.)

In West, supra, 139 Cal.App.3d 606, the requested instruction listed eight factors for the jury to consider in determining whether there was reasonable doubt as to the identification of the defendant as the perpetrator. ( Id., at p. 609.) It would have instructed the jury to consider evidence relating to such factors as the witness's opportunity to observe the alleged criminal act, the stress under which the witness made the observations, the cross-racial nature of the identification, and whether the witness had an uncorrected vision deficiency. The West instruction has been formalized, with the addition of several other factors (including the length of time between the alleged criminal act and the witness's identification, and whether the witness had prior contacts with the alleged perpetrator) in CALJIC No. 2.92 (4th ed. 1987 pocket pt.), entitled "Factors to Consider in Proving Identity by Eyewitness Testimony." This model instruction, with appropriate modifications to take into account the evidence presented at trial, will usually provide sufficient guidance on eyewitness identification factors. (CALJIC No. 2.92 is set out in the appendix.)

(6) As we stated in McDonald, supra, "the defendant may be entitled to a special instruction specifically directing the jury's attention to other evidence in the record — e.g., facts developed on cross-examination of the eyewitnesses — that supports his defense of mistaken identification and could give rise to a reasonable doubt of his guilt." (37 Cal.3d at p. 377, fn. 24, italics added.) We now reach the issue we avoided in McDonald, the correct wording of such an instruction. (7a) We hold that a proper instruction on eyewitness identification factors should focus the jury's attention on facts relevant to its determination of the existence of reasonable doubt regarding identification, by listing, in a neutral manner, the relevant factors supported by the evidence.

The instruction should not take a position as to the impact of each of the psychological factors listed. We disagree with the dissent's suggestion that CALJIC No. 2.92 is "deficient" for failing to explain the effects of the enumerated factors. ( Post, p. 1157.) An instruction that "explained" the influence of the various psychological factors would of necessity adopt the views of certain experts and incorporate the results of certain psychological studies while discounting others. It would require the trial judge to endorse, and require the jury to follow, a particular psychological theory relating to the reliability of eyewitness identifications. Such an instruction would improperly invade the domain of the jury, and confuse the roles of expert witnesses and the judge.

McDonald, supra, 37 Cal.3d 351, contrary to the dissent's implication ( post, p. 1158), does not justify such an "explanatory" instruction. In McDonald, we endorsed only the use of expert testimony to put before the jury the scientific and psychological evidence as to factors believed relevant to an evaluation of eyewitness identifications. (8) As explained in McDonald, the use of expert testimony may assist the jury in its task of evaluating the testimony and other evidence before it, without usurping the jury's functions of determining the credibility and qualifications of the witnesses, and affording their testimony the appropriate weight. (37 Cal.App. 3d at pp. 369-371.) Expert witnesses may be called by both parties, thus enabling the jury to hear both sides of the scientific theories regarding eyewitness identifications. Questioning can focus on the psychological factors most relevant to the particular circumstances of the case, thereby avoiding presenting the jury with potentially inaccurate overgeneralizations. Further, cross-examination of experts can reveal the weaknesses in their testimony and theories, as well as the underlying assumptions on which their conclusions are based.

The scientific studies on the psychological factors affecting eyewitness identifications are sufficiently experimental and open to debate that most courts are still reluctant to approve even the admission of expert testimony on the subject. (E.g., State v. Ward (Tenn. Cr. App. 1986) 712 S.W.2d 485, 487 ["The great weight of authority in this country is that the study of the reliability of eyewitness identification has not attained that degree of exactitude which would qualify it as a specific science. . . . We are of the opinion that there are too many variables involved including individual power of observation, individual reaction to stress or the threat of violence, the visual acuity of a particular witness, as well as numbers of general, common factors unamenable to charting and categorizing."]; United States v. Poole (9th Cir. 1986) 794 F.2d 462, 468 [upholding rejection of expert testimony on eyewitness identifications where trial court "questioned the scientific basis for the proffered testimony," and "commented that the proffered testimony was general . . . and believed that general testimony, not tied to the specific testimony in the case, would not be helpful to the jury."]; Bloodsworth v. State (1986) 307 Md. 164 [ 512 A.2d 1056, 1064] [refusal to admit expert testimony on eyewitness identification factors not error, given that "[t]he vast majority of courts have rejected" such testimony]; United States v. Downing (E.D. Pa. 1985) 609 F. Supp. 784, 790-791 [finding proffered expert testimony not sufficiently reliable to warrant its admission under Fed. R. Evid. 702, and disagreeing with the statement in McDonald, supra, 37 Cal.3d at p. 365 (relied on by the dissent, post, at pp. 1157-1158), that the results of studies in the area of eyewitness identification factors were consistent: "With due deference to the . . . Supreme Court of California, the testimony presented at the evidentiary hearing held by this court belies such consistency." The court listed areas in which the results of studies have been inconsistent, including theories as to the rate at which memory diminishes, the assimilation factor and the confidence-accuracy ratio.].)

Unlike a jury instruction, expert testimony is not binding on the jury. In McDonald, we observed, "the jury remains free to reject [ the expert testimony] 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." (37 Cal.3d at p. 371, italics added, fn. omitted.) CALJIC No. 2.80 tells the jury in part, "You are not bound to accept an expert opinion as conclusive, but should give to it the weight to which you find it to be entitled. You may disregard any such opinion if you find it to be unreasonable."

In contrast, an instruction incorporating a particular expert's opinion would deprive the jury of its independence in judging the weight to be given to such expert opinion. The dissent can cite no authority, and we have found none, to support endorsing an expert opinion, via jury instruction, on a matter of ongoing scientific debate. (See fn. 13, ante, and cases cited.)

(7b) We conclude that the listing of factors to be considered by the jury will sufficiently bring to the jury's attention the appropriate factors, and that an explanation of the effects of those factors is best left to argument by counsel, cross-examination of the eyewitnesses, and expert testimony where appropriate. The instruction should list the applicable factors in a neutral and nonargumentative instruction, thus effectively informing the jury without improperly invading the domain of either jury or expert witness. It should list only factors applicable to the evidence at trial, and should refrain from being unduly long or argumentative.

The Kansas Supreme Court came to a similar conclusion recently when confronted with an argument that the effects of the factors must be explained. In State v. Wheaton (1986) 240 Kan. 345 [ 729 P.2d 1183], the court rejected a challenge to the Kansas model jury instruction, which lists "the factors which could affect the accuracy of the identification made by an eyewitness," including the witness's opportunity to observe, emotional state, prior contact with defendant, and degree of certainty. ( Id., at p. 1185.) In that case, the model "factors" instruction was given, but the defendant argued that it was insufficient, because it did "not explain to the jury how to use the factors, e.g., that threat of violence decreases the accuracy of the identification rather than increases its accuracy, as many laymen believe." ( Id., at p. 1188.) Defendant argued that the trial court erred in ruling expert testimony describing these effects was inadmissible. The Supreme Court disagreed, holding the trial court's decision was not error, in part because expert testimony was not necessary to explain the effects of the factors. It stated, "Extensive cross-examination of the eyewitnesses and persuasive argument by defense counsel can highlight any inaccuracies which could result because the eyewitness was being threatened or was under stress." ( Ibid.)

In People v. Martinez, supra, 191 Cal.App.3d 1372, the court gave CALJIC No. 2.92, after first providing defense counsel an opportunity to suggest additional factors to supplement those listed in the standard instruction. ( Id., at p. 1383.) This procedure will generally be a proper one. In Martinez, the defendant declined to add any factors to CALJIC No. 2.92. ( Ibid.) The Court of Appeal held that it was not error for the court to reject an additional and lengthy " Guzman-like instruction" requested by the defendant, because "the factors and criteria set forth in [the requested instruction] have been sufficiently incorporated in CALJIC No. 2.92.'" ( Ibid.) The court correctly noted, "The concern of the court in Guzman was that the trial court instruct on the `factors that affect eyewitness identification testimony, as they relate to reasonable doubt.' [Citation.] CALJIC No. 2.92 clearly focused the jury's attention on such factors." ( Id., at p. 1384.) (9) CALJIC No. 2.92 or a comparable instruction should be given when requested in a case in which identification is a crucial issue and there is no substantial corroborative evidence. (See McDonald, supra, 37 Cal.3d at p. 377 [eyewitness expert testimony appropriate "[w]hen 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 in such a case the defendant also may be entitled to a special instruction on eyewitness identification factors].)

(5b) In this case, defendant's requested instruction No. 3, like CALJIC No. 2.92, avoids being "too long and argumentative." Although based on the Telfaire-Guzman instruction, it is a much condensed version of that charge; and rather than drawing factual inferences favorable to defendant from specific items of testimony, it "merely intone[s] considerations any jury must make in evaluating any eyewitness identification." ( People v. Guy, supra, 107 Cal.App.3d 593, 603.) As drafted in the present case, the instruction does not err by referring to factors unsupported by the evidence. (Cf. People v. Hall, supra, 28 Cal.3d 143, 159.) Therefore, we hold the court erred in refusing to give defendant's special instruction No. 3.

Defendant's requested instruction omits some of the factors listed in CALJIC No. 2.92. Because we hold it was harmless error to fail to give any instruction at all on the factors relevant to eyewitness identifications, we need not discuss whether it was error to decline to instruct the jury respecting factors not listed in the requested instruction. (Cf. People v. Coates, supra, 152 Cal.App.3d 665, 670-671 [finding it was not error to reject a requested instruction which was improper as drafted, but that it was error to fail to cure the inadequacy of the requested instruction and give a properly tailored instruction, the court engaged in a harmless error analysis on the latter error].)

2. The Error Was Harmless

(10a) Although the court erred in not giving defendant's requested "factors" instruction, the error was not prejudicial. (11) This error requires reversal only if "the court, `after an examination of the entire cause, including the evidence,' is of the `opinion' that it is reasonably probable that a result more favorable to [defendant] would have been reached in the absence of the error." ( People v. Watson (1956) 46 Cal.2d 818, 836 [ 299 P.2d 243].)

(10b) Our consideration of the entire record in this case leads us to conclude that it is not reasonably probable that had the requested instruction been given, the jury would have reached a verdict more favorable to defendant. We base this holding on (a) the overall strength of the evidence; (b) the fact that factors relating to the reliability of the eyewitness identifications were brought to the jury's attention by (i) cross-examination, (ii) opening and closing arguments of counsel, and (iii) the jury instructions given; and (c) the absence of any indication that the jury was uncertain or confused.

Our evaluation is based on the entire record, and we do not mean to imply that any one of these factors alone is determinative on the question of prejudice.

(a) Overall Strength of the Evidence

The evidence as a whole was sufficiently convincing to warrant sustaining the guilty verdict. As noted, three of the eleven victims identified defendant as one of the robbers. Although there was no evidence corroborating the eyewitness identifications, neither did any eyewitness testify at trial that defendant was not one of the robbers, as specifically occurred in McDonald, supra, 37 Cal.3d 351. (In McDonald, an eyewitness, the same race as defendant, testified she had no doubt that defendant was not the perpetrator. [ Id., at pp. 359-361.]) The witnesses in this case who were unable to recognize defendant were for the most part unable to describe the faces of any of the robbers. On this basis the facts of the present case are distinguishable from cases such as McDonald, supra, and West, supra, 139 Cal.App.3d 606, 608, in which at least one eyewitness testified unequivocally that the defendant was not the perpetrator. Indeed, we stated explicitly in McDonald that our finding of prejudicial error was based in part on the fact that the evidence as to identity "was close, given the potential weaknesses in the prosecution's testimony and the presence of both eyewitness and alibi testimony favorable to the defense." (37 Cal.3d at p. 376, italics added, fn. omitted.)

Defendant does not argue that the evidence was insufficient to support his conviction. Neither does he challenge the propriety of the pretrial identifications.

The exception is Janice Tong, who gave a positive identification of the codefendant but said she got a good look at only that one man. Other witnesses could describe only the robbers' clothing and guns.

In addition, in this case, defendant's alibi evidence was not strong and could reasonably have been discounted by the jury. (See ante, fn. 2.) This also distinguishes the present case from McDonald, in which the alibi evidence was substantially stronger. In McDonald, six witnesses testified that the defendant had been in Alabama visiting his family for several weeks, including on the day that the California murder of which he was accused took place. Postcards mailed by defendant while en route to Alabama, and telephone bills of defendant's Alabama relatives for the relevant dates, were introduced as corroborative evidence as to his location. (37 Cal.3d at p. 360.)

(b) Factors Affecting Reliability of Eyewitness Identification Testimony

The factors listed in defendant's requested instruction (relating to the circumstances of the original observation, circumstances of subsequent identifications, and other inconsistent identifications) were put before the jury at trial by means of several vehicles: cross-examination, counsel's arguments, and the instructions the court gave.

Defendant, citing United States v. Hodges (7th Cir. 1975) 515 F.2d 650, argues that cross-examination and counsel's arguments cannot substitute for an instruction on eyewitness identification factors. In Hodges, however, the trial court refused to give any instruction on eyewitness identification, even though identification was the sole issue in the case. The circuit court held that the trial court should have instructed the jury to acquit if it had a reasonable doubt as to the identity of the pertpetrator, and that because it failed to give any identification instruction, counsel's cross-examination and arguments did not suffice "to focus the jury's attention on the issue of identity." ( Id., at p. 653.)
A later Seventh Circuit case, United States v. Anderson (7th Cir. 1984) 739 F.2d 1254, held it was not reversible error for the trial court to refuse to give the Telfaire instruction when the court used a comparable, though less detailed, instruction. Anderson states that as long as the jury charge calls the jury's attention to the importance of the witness's opportunity to observe the offender, his ability to make later identifications, and the circumstances of the later identifications, the court need not give the longer Telfaire instruction. The Anderson court concluded: "Counsel may develop the relevant details through cross-examination and argument." ( Id., at p. 1258; see also United States v. Ramirez-Rizo (5th Cir. 1987) 809 F.2d 1069, 1072 [failure to give eyewitness instruction not reversible error when analyzed in the context of the trial as a whole, including the other instructions given, counsel's argument, and cross-examination].)

(i) Cross-examination

The 11 eyewitnesses to the robbery testified over the course of 5 days. Counsel for defendant and codefendant interrogated the witnesses extensively on their ability to see and identify the robbers during the robbery, and on the circumstances of their subsequent identifications. They succeeded in thoroughly highlighting the factors relevant to the reliability of the eyewitness identifications.

Cross-examination of the three witnesses who identified defendant focused on the factors listed in defendant's requested instruction. For example, Peter Marino, who identified defendant at a photo lineup on the day of the robbery, admitted on cross-examination that at the robbery he could not see the robbers' faces very well, and that he could not distinguish their features through the masks. He candidly admitted, "you don't get a full look at everybody and you're scared," and acknowledged the distraction caused by other employees screaming and yelling. Marino also conceded that, at defendant's preliminary hearing, he had testified that he saw defendant in court the week before the hearing, and that defendant at that time did not appear to be the same man whose photograph he had selected. In addition, defense counsel impeached Marino by reading from his testimony at the codefendant's preliminary hearing, in which Marino, when asked to select from a group of photographs the photo he had selected at the lineup on the day of the robbery, instead picked a photograph of someone other than defendant. Finally, Marino stated that his in-court identification of defendant was based on the photograph he had selected at the original photo spread.

"Q: [Y]ou didn't get a good enough look at anybody to positively ID anyone as being one of those robbers, did you? [¶] A: Not on a front face configuration, no. [¶] Q: You didn't get a very good look at anybody's face, is that right? [¶] A: That's right."

Stephanie Sung, who opened the safe for the robbers, stated she came face to face with defendant, and that she could see his face despite her extreme nervousness. At trial, after defendant pulled a stocking mask over his face, she positively identified him as one of the robbers. Sung stated that based on that in-court view of defendant, she believed he was the robber she had seen while opening the safe. On cross-examination, she admitted that when she had selected defendant's photo from a photo layout after the robbery, she had said only that the man in the picture "looked like" the robber, and had not stated defendant actually was the robber. Further, at the subsequent live lineup, she had not been sure enough of her identification to pick out defendant. She stated she had been 75 percent certain at the lineup, but at trial was 100 percent certain defendant was one of the robbers she saw.

The third witness, Erica Albertsen, also made an in-court identification of defendant. She testified that she had identified him in a police lineup seven to ten days after the robbery. Defense counsel questioned her closely on the extent of her opportunity to observe the robber. Albertsen testified she could see the robber's face as he came into her office, ran around the back of her chair, and then pushed her to the floor. She admitted being "scared and startled." Defense counsel, reading from the preliminary hearing transcript in which Albertsen had stated the robber's height was "five-seven," noted that at trial she changed her description to "five-eight, five-nine." Also, at the preliminary hearing Albertsen had described the robber's skin color as "medium," whereas at trial she changed it to "lighter than medium." In addition, she testified that she had failed to give a complete description of the robber to the police inspector or anyone else before defendant's preliminary hearing. She stated that this was because no one had asked her for such a description up to that point.

Finally, she admitted she had not selected defendant's photo from the photo lineup, but insisted his photo had not been in that lineup. From the evidence, it is uncertain whether Albertsen was shown defendant's photo. The inspector who originally displayed the photo spreads gave conflicting testimony about whether he showed defendant's photo to all the victims.

In addition, the eight employees who could not identify defendant all testified. Most of them stated that they were unable to discern or describe the features of the robbers. Their cross-examination focused on the factors contributing to their inability to identify defendant, such as poor eyesight, the stress of the event, their fear, concealment of the robbers' faces by masks, and the fact that the witnesses were lying on the floor looking down or were concentrating on the robbers' guns rather than their faces.

(ii) Defense Counsel's Arguments

Counsel's closing arguments spanned over 100 pages of trial transcript. Defendant's attorney thoroughly detailed the potential unreliability of eyewitness identifications. She cautioned the jurors to pay special attention to the difficulty of identifying someone wearing a stocking mask, and pointed out inconsistencies and ambiguities in the eyewitnesses' statements, both during and before trial. In addition, she emphasized that eight of the victims could not identify defendant. Counsel admonished the jury to remember that at the photo spread soon after the robbery — their first chance to identify the robbers — none of the victims positively identified defendant. She argued specifically that Erica Albertsen had seen defendant's photograph at the initial spread and failed to recognize him. (Cf. People v. Walker (1986) 185 Cal.App.3d 155, 167 [ 229 Cal.Rptr. 591] [refusal to admit expert testimony on eyewitness identifications was harmless error, in part because defense counsel's argument carefully reviewed the facts, "including the weakness of the eyewitness identification focusing on the psychological factors and unreliability of eyewitness identifications as they applied to (defendant.)"].)

Codefendant's counsel warned the jury expressly: "This is an eyewitness case. Eyewitness is traditionally thought to be the least reliable of any evidence." He pointed out that in eyewitness cases the jury received three instructions on reasonable doubt (CALJIC Nos. 2.90, 2.91, 4.50) because "these cases are fraught with danger" of misidentification.
Codefendant's counsel also noted the inherent danger of inaccuracy of a cross-racial identification. The robbers were Black. Codefendant was identified only by Ms. Tong, an Asian. The record does not explicitly state the races of the eyewitnesses who identified defendant, and defendant's requested instruction No. 3 did not list the cross-racial nature of an identification as a factor to consider.

Finally, defense counsel cited documented examples of convictions based on mistaken identifications, and described the results of a psychological study demonstrating that a person's recollection of what he has seen may change over time. She emphasized that four months had passed between the robbery and the trial, and that the witnesses' recollections could be mistaken.

(iii) Jury Instructions Given

The court gave a variety of instructions relevant to eyewitness identifications. (12) Although the giving of the general instructions may not alone preclude reversal for failure to give a specific eyewitness factor instruction ( People v. West, supra, 139 Cal.App.3d at p. 610), their use is relevant, in combination with counsel's arguments and cross-examination, to a determination of whether the error was prejudicial. (See People v. Coates, supra, 152 Cal.App.3d 665, 671.) (10c) In this case, the court's instructions essentially covered each area of concern addressed in defendant's requested instruction No. 3, albeit with less specificity than the requested instruction.

On the witnesses' ability to observe the robbers, the court instructed the jurors at both the opening and close of trial that they were the "sole judges of the believability of the witnesses . . . and the weight to be given to the testimony of each," and that in determining believability of a witness they could consider " the witness' opportunity and ability to see and hear any matter about which he or she testifies and the witness' ability to remember and relate those matters here in court. . . ." (CALJIC No. 2.20, as modified by the court, italics added.) In addition, before deliberations, the judge instructed that a witness's observations may be unreliable: "It is a fact, also, that two people who witness an incident or a transaction often may see or hear it differently." (CALJIC No. 2.21, italics added.) He further informed the jury that when determining the weight to be given to a witness's opinion, "you should consider his or her credibility, the extent of the witness' opportunity to perceive the matters upon which the opinion is based, and the reasons, if any, given for it." (CALJIC No. 2.81, italics added.)

On the reliability of subsequent identifications, the court explained the prosecutor bore the burden of proving beyond a reasonable doubt that it was defendant who had committed the crimes in question. "You must be satisfied beyond a reasonable doubt of the accuracy of the identification of each defendant as the person who committed the offense before you may convict him. If, from the circumstances of the identification, you have a reasonable doubt whether a defendant was the person who committed the offense, then you must give the defendant the benefit of the doubt and find him not guilty." (Former CALJIC No. 2.91, italics added.)

At another point, the court focused on the issue of prior inconsistent or erroneous identifications. It instructed the jury that in weighing the testimony, it could consider "any statement previously made by a witness that is either consistent with any part of his or her testimony or any statement which is inconsistent with any part of the witness' testimony." (CALJIC No. 2.20, as modified by the court, italics added.)

Finally, in its instruction on the defense of alibi, the court referred to the possibility of misidentification, telling the jury: "If, after a consideration of all of the evidence, you have a reasonable doubt that a defendant was present at the time that the crime was committed, [the defendant] is entitled to an acquittal." (CALJIC No. 4.50, italics added.)

Although these instructions did not list such specific factors as stress, lighting, and length of time available for the original observation, they directed the jury's attention to the issue of the reliability of the identifications, and generally covered the areas on which defendant's requested instruction focused. In addition, as described above, counsel's extensive cross-examination and arguments further amplified the instructions given, and placed before the jury the factors specifically enumerated in the requested instruction.

We do not disregard the well-established difference between jury instructions, evidence, and argument. Highlighting the factors through cross-examination and argument will not necessarily alleviate the need for a factor instruction nor will it always cure any error in failing to give such an instruction. Here, however, the fact that the factors listed in defendant's requested instruction were amply presented to the jury at trial through other vehicles, in combination with the related general instructions, leads us to conclude the error was harmless.

(c) No Indication of Jury Confusion

The presentation of evidence in this case took about eight days. The jury deliberated less than one day before finding defendant guilty. It did not manifest any confusion over defendant's case; it never asked for clarification of instructions or rereading of transcripts, nor did it indicate any problem reaching a verdict as to defendant.

Deliberations started at 10:12 a.m. A requested rereading of testimony, relating to codefendant only, took place from 2:42 to 3 p.m. The jury returned its guilty verdict as to defendant at 4:45 p.m. the same day.

In contrast, the jury did demonstrate uncertainty concerning the guilt of the codefendant. It requested a rereading of testimony relating only to the codefendant, and, although finding defendant guilty on all counts, concluded it had reached an "impasse" with respect to the codefendant. Because the evidence against the codefendant, like that against defendant, was limited to eyewitness identification, the difference in outcome indicates that the jury thoughtfully considered all the evidence before it, and individually evaluated the strength of the eyewitness evidence against each of the two defendants. In this respect, this case is similar to Walker, supra, 185 Cal.App.3d at page 166, in which the court's rejection of expert testimony on eyewitness identifications was held harmless error based in part on the brevity of the jury deliberations (about one day after a six-day trial). The Walker court also found it significant that the jury acquitted the codefendant on one count, indicating the jury's "concern with reaching a fair result." ( Ibid.)

Contrary to the dissent's characterization ( post, p. 1164), the evidence against the codefendant was not necessarily stronger than that against defendant Wright. Janice Tong, the sole witness to identify the codefendant, was described by witnesses as being "hysterical" during the robbery, and admitted that although she was nearsighted she was not wearing her glasses at the time of the robbery. In addition, several aspects of her trial testimony contradicted testimony of others of the victims, and also contradicted her own preliminary hearing testimony. As counsel aptly put it, in closing argument, "Janice Tong is reasonable doubt personified."

The lack of jury confusion distinguishes this case from cases more closely balanced on the evidence. Compare West, supra, 139 Cal.App.3d 606, in which the jury asked for a rereading of a substantial portion of the testimony, and some instructions, and at one point reported itself deadlocked. ( Id., at p. 610.) There the court noted that the jury's requests for clarification demonstrated "the closeness of this case" and that therefore the error could not be deemed harmless. ( Ibid.) In McDonald, supra, 37 Cal.3d 351, the jury deliberated 19 1/2 hours after hearing evidence that took only 6 hours to present. We stated that when jurors "deliberate in these circumstances for more than three and a half times longer than it took to put on the entire prosecution and defense cases, we may fairly infer they found the issue difficult to decide." ( Id., at p. 376, fn. 23; cf. Walker, supra, 185 Cal.App.3d at p. 166.) Similarly, in People v. Coates, supra, 152 Cal.App.3d 665, the court, in finding the failure to instruct on eyewitness identification factors prejudicial, found it significant that the jury sought a rereading of evidence and the reasonable doubt instruction. The court stated, "[It] is as though the jurors themselves were requesting a more detailed instruction on the subject of identification, the only issue in the case." ( Id., at p. 672.) No such inference of jury confusion can be drawn here.

In sum, the record reveals that the factors listed in defendant's requested instruction were adequately presented to the jury at trial, and that accordingly the failure to give requested instruction No. 3 was harmless error. In the course of questioning the witnesses who identified defendant, defense counsel elicited testimony on the difficulty of seeing the robbers through their stocking masks, the fear and panic the witnesses felt during the robbery, and their initial uncertainty about the identification of defendant. In argument, both defense attorneys stressed the unreliability of eyewitness identifications, and specifically emphasized the factors relevant to the reliability of the eyewitness identifications and supported by the evidence. Further, the trial court instructed the jury on the credibility of witnesses, the reliability of witnesses' opinions, and the burden of proof, which, in combination with the specific factors brought out by defense counsel, thoroughly informed the jury of the issues involved in its determination of defendant's guilt. Finally, the jury distinguished between defendant and codefendant, demonstrating that it carefully assessed the strength of the identification evidence against each of them. It seems apparent that as to defendant the jury found the eyewitness testimony credible, even in light of all the factors that were brought out at trial, and that it found defendant's alibi unpersuasive. We hold it is not reasonably probable that a verdict more favorable to defendant would have resulted had the court given defendant's requested instruction No. 3.

D. Defendant's Proposed Cautionary Instruction

(13a) Defendant's proposed instruction No. 5 would advise the jury that eyewitness identification testimony may be mistaken and "should be received with caution." We hold this instruction was properly refused.

The requested instruction reads: "Where the prosecution has offered identification testimony, that is, the testimony of an eyewitness that he saw the defendant commit the act charged, such testimony should be received with caution. An identification by a stranger is not as trustworthy as an identification by an acquaintance. Mistaken identification is not uncommon, and careful scrutiny of such testimony is especially important."

No California case has held that such a cautionary instruction is required in addition to the eyewitness "factors" instruction. (14) As stated in People v. McCowan, supra, 85 Cal.App.3d at page 679, an instruction stating that mistaken identification is "not uncommon" is objectionable and may be properly rejected because it "does not state a principle of law or establish a basis for instructing a jury." (But see Martinez, supra, 191 Cal.App.3d 1372, 1381 ["Assuming, arguendo," it was error to refuse to admonish the jury to consider with caution eyewitness identification testimony, any error was harmless because the eyewitnesses were "thoroughly cross-examined" and the jury was given general instructions including CALJIC Nos. 2.20 and 2.92].)

We are aware of no jurisdiction in which a cautionary instruction such as defendant's No. 5 has been deemed appropriate. In fact, at least one other court that considered such an instruction expressly rejected it. In State v. Watson (W. Va. 1984) 318 S.E.2d 603, the defendant was charged with breaking and entering. The only testimony placing him in the burglarized home was that of an 11-year-old child. Although the court held that the defendant was entitled to a specific instruction on identification, it refused a request for a special cautionary instruction similar to that requested here. ( Id., at pp. 614-615.) The West Virginia Supreme Court of Appeals reasoned in part that the proposed cautionary instruction was essentially premised on "the theory that any eyewitness testimony is suspect, [which is] a legal point that we believe is too broad." ( Id., at p. 615.)

The proposed special cautionary instruction in Watson provided: "`[W]here the prosecution has offered identification testimony, that is, the testimony of an eyewitness that she saw the Defendant commit the act charged, such testimony shall be received with caution. An identification by a stranger is not as trustworthy as an identification by an acquaintance. Mistaken identification is not uncommon. The witness' opportunity to observe the perpetrator during the commission of the act charged is of great importance in determining the credibility of her identification. Testimony of the witness that she is positive of her identification may be considered by you, but does not relieve you of the duty to carefully consider her identification testimony and to reject it if you find that it is not reliable. Careful scrutiny of such testimony is especially important when, as in this case, it is the only testimony offered by the prosecution to connect the Defendant with the act charged.'" ( State v. Watson, supra, 318 S.E.2d at p. 615, fn. 15.)

(13b) Defendant's requested instruction No. 5 is both improper and unnecessary. A special cautionary instruction is unnecessary because the "factors" instruction already required properly highlights the factors relevant to defendant's concerns about the reliability of eyewitness identification testimony in a particular set of circumstances.

The additional general cautionary instruction requested here would produce redundancies which could unbalance the jury's deliberative process. Singling out a category of evidence for special consideration may cause the jury to give it undue weight in its deliberations. The cautionary instruction given along with the factors instruction would place unwarranted emphasis on the eyewitness identification, and likely give the jury the improper impression that the court considers the eyewitness identification evidence not only particularly important but also overwhelmingly suspect.

The requested cautionary instruction would also improperly usurp the jury's role as the exclusive trier of fact by binding it to the view that eyewitness identifications are often mistaken. It goes beyond previously approved cautionary instructions by informing the jury not only that it should view the eyewitness identification evidence with caution, but also that such evidence is frequently unreliable and misidentification is "not uncommon." This is not an appropriate function of an instruction. If the defendant wishes to present to the jury information on the unreliability of eyewitness identifications under a particular set of circumstances, he must use means other than a jury instruction, such as expert testimony. (See McDonald, supra, 37 Cal.3d 351.) As we stated ante, expert testimony has the advantage of being subject to cross-examination and rebuttal, thus allowing the jury to determine for itself the weight it should give to expert opinions, rather than binding the jury to accept certain experts' views.

Compare the language of defendant's proposed instruction No. 5 with the following cautionary instructions: CALJIC No. 2.27 — Sufficiency of Testimony of One Witness ("Testimony which you believe given by one witness is sufficient for the proof of any fact. However, before finding any fact [required to be established by the prosecution] to be proved solely by the testimony of such a single witness, you should carefully review all the testimony upon which the proof of fact depends.");
CALJIC No. 2.71 — Admission Defined ("An admission is a statement made by defendant other than at his trial which does not by itself acknowledge his guilt of the crime(s) for which he is on trial, but which statement tends to prove his guilt when considered with the rest of the evidence; [¶] You are the exclusive judges as to whether the defendant made an admission, and if so, whether such statement is true in whole or in part. If you should find that the defendant did not make the statement, you must reject it. If you find that it is true in whole or in part, you may consider that part which you find to be true. [¶] Evidence of an oral admission of the defendant should be viewed with caution."); and
CALJIC No. 3.18 — Testimony of Accomplice to be Viewed with Distrust ("The testimony of an accomplice ought to be viewed with distrust. This does not mean that you may arbitrarily disregard such testimony, but you should give to it the weight to which you find it to be entitled after examining it with care and caution and in the light of all the evidence in the case.").

In sum, the eyewitness "factors" instruction provides the jury with sufficient means to evaluate eyewitness identification testimony and alerts jurors to the factors that may affect eyewitness identifications. In addition, expert testimony may be used when appropriate to further elucidate the effect of the factors listed. Accordingly, we reject the use of a special additional and cumulative cautionary instruction regarding the unreliability of eyewitness identification. The trial court did not err in refusing to give this requested instruction.

III. DISPOSITION

For the reasons discussed above, we hold that the trial court did not commit reversible error. The judgment is affirmed in its entirety.

Panelli, J., Arguelles, J., Eagleson, J., and Kaufman, J., concurred.