I
During the trial the prosecution introduced the testimony of three witnesses who claimed to have seen the appellant in the ballpark one week before the abduction, two witnesses who claimed to have seen the appellant in the park on the day Krista was kidnapped, and one who claimed to have seen the appellant leaving the site where the body was found.
The testimony of the ballpark witnesses was inconsistent and contradictory. The ballpark witnesses did not agree about whether one of them argued or merely conversed with a spectator, whether the spectator stood, sat or squatted, or whether one of the three of them had actually observed the spectator at all. Two of the three witnesses identified the ap*128pellant as the spectator only after seeing him on television and in the newspapers and only after discussing between themselves whether the appellant, as viewed on television, was the spectator they saw in the park some sixteen months earlier. Each of these witnesses testified that at most they observed the appellant for less than one minute.
Stephanie Baker, who also saw the abductor in the park, and Roy Wilson gave similar descriptions of Krista’s kidnapper, but each selected the same incorrect picture from photo arrays which included the photo of appellant. Neither could identify the appellant in court.
The final identification witness, Donald J. Middleton, claimed to have seen a man driving a raspberry-colored car away from the shed where Krista’s body was found. Middleton stated that he observed the man from his pick-up truck as they passed on opposite sides of the road. This observation lasted less than five seconds. The description Middleton gave to police included physical details significantly different from those of the appellant. When shown a photo array a few days after Krista’s death, Middleton was not able to select anyone. Sixteen months later, Middleton identified the appellant when shown a picture of a van, the appellant and a car, and after seeing the appellant on television.
Appellant sought to introduce the testimony of an experimental psychologist, Steven Penrod, (1) with regard to factors involved in the mental processes of identifications generally, and (2) to render his opinion about the accuracy and credibility of the specific identification testimony of four of the witnesses. Upon the trial court’s ruling that Penrod’s testimony was inadmissible, it was proffered by the appellant for review on appeal.
The prosecutor successfully argued against the admission of Penrod’s testimony, citing the holding in State v. Sims (1981), 3 Ohio App. 3d 321. Specifically, that court held as reflected in paragraph two of the syllabus:
“The expert testimony of an experimental psychologist concerning the statistical likelihood of eyewitnesses to observe and recall accurately the details of a crime is not admissible, on the ground that such testimony does not assist the trier of fact to determine the facts in the case before it. * *
Appellant contends that the holding in Sims should be limited to the particular facts of that case and urges this court to find: (1) that expert psychological testimony regarding factors which may impair the accuracy of typical eyewitness identifications are admissible under Evid. R. 702; (2) that expert psychological testimony regarding the credibility of the identification testimony of a particular witness is admissible under Evid. R. 702; and (3) that the failure of the trial court to allow the proffered testimony in this case was an abuse of discretion.
Evid. R. 702 provides:
“If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a *129witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.”
The Staff Note to this rule characterizes it as an embodiment of the general rule regarding admissibility of testimony from expert witnesses generally, and recites the principle underlying the rule as articulated in Hartford Protection Ins. Co. v. Harmer (1853), 2 Ohio St. 452, 456-457:
“* * * In everything pertaining to the ordinary and common knowledge of mankind, jurors are supposed to be competent, and, indeed, peculiarly qualified to determine the experienced connection between cause and effect, and to draw the proper conclusion from the facts before them. But they are selected with no view to their knowledge of particular services, trades, and professions, requiring a course of previous study and preparation. As questions connected with these will very often arise, and as the law deprives the jury of no reliable means for ascertaining the truth, it allows them to be aided, in making the proper application, by the opinions of witnesses possessing peculiar skill in those particular departments. * * *” (Emphasis added.)
The appellant contends, and we agree, that the standard for determining whether expert testimony is admissible is whether it will assist the trier of fact in assessing the weight to be given a particular witness. However, in agreeing with appellant, we do not disagree with the Sims court’s decision as cited above, but rather we find that ruling misapplied here.
In Sims, the psychologist presented the results of an experiment involving student identifications of the perpetrator of a mock crime. The highest accuracy level achieved by these eyewitnesses was sixty-five percent. The Sims court at 325 ruled that:
“* * * This information, however, is irrelevant to the issue of the guilt of the accused in the case at bar, because there are no statistics on the probability of misidentification by eyewitnesses in cases which are strong enough to be brought to trial. Even if such statistics were available, this court is not persuaded that such information would assist the trier of fact to assess the credibility of the witnesses in the particular case before it.” (Emphasis added.)
In footnote 6 at 325 the court added:
“The statistical likelihood of eyewitnesses to err would seem analogous to the statistical likelihood of a paid informant to lie, or the statistical likelihood that the family of a defendant would consciously or unconsciously fabricate an alibi for the defendant. Such evidence would not assist the trier of fact to determine whether a particular eyewitness, informant, or alibi witness is telling the truth.” (Emphasis added.)
We agree with the court’s analysis in Sims. Further, it appears to this court that this kind of testimony is rarely likely to pass the test of relevancy under Evid. R. 401 and the exclusory provisions of Evid. R. 403(A). On the other hand, the proffered testimony in this case proposed, in part, *130to apprise the jury of the factors which are likely to affect the processes involved in memory. The admissibility of this kind of testimony rests, at least in part, upon whether such information is within the general knowledge of the jury. Appellant cites several cases which persuade us that such generalized testimony could be helpful to a jury and should not be held as inadmissible in every instance.
In United States v. Smith (C.A. 6, 1984), 736 F. 2d 1103, certiorari denied (1984),_U.S._, 83 L. Ed. 2d 143, an Ohio case, the defendant attempted unsuccessfully to introduce the testimony of an experimental psychologist whose testimony would have provided the jury with insight into an eyewitness’ general inability to perceive and remember what is seen under a stressful situation. The Sixth Circuit Court of Appeals rejected the district court’s conclusion that the “ ‘jury is fully capable of assessing the eyewitnesses’ ability to perceive and remember,’ ” {id. at 1105) and stated:
“Such testimony might have been relevant * * * and not only might have assisted the jury, but might have refuted their otherwise common assumptions about the reliability of eyewitness identification.” (Emphasis sic.) Id., at 1106.
Similarly, in United States v. Downing (C.A. 3, 1985), 753 F. 2d 1224, the Third Circuit Court of Appeals rejected the district court’s conclusion that the testimony of an expert in the field of human perception and memory was inadmissible, because such testimony could never meet the “helpfulness” requirement of Fed. R. Evid. 702.5 The appellate court held that expert testimony, which informed the jury about such variables as “(1) the ‘forgetting curve,’ i.e., the fact that memory does not diminish at a uniform rate; (2) the fact that, contrary to common understanding, stress causes inaccuracy of perception and distorts one’s subsequent recall; (3) the ‘assimilation factor,’ which indicates that witnesses frequently incorporate into their identifications inaccurate information gathered after the event and confused with the event; (4) the ‘feedback factor,’ which indicates that where identification witnesses discuss the case with each other they can unconsciously reinforce their individual identifications; and (5) the fact that studies demonstrate the absence of a rela*131tionship between the confidence a witness has in his or her identification and the actual accuracy of that identification” (id. at 1230) could be helpful. The court stated that “[e]ach of these ‘variables’ goes beyond what an average juror might know as a matter of common knowledge, and indeed some of them directly contradict ‘common sense.’ ” Id. at 1230-1231.
The Downing court was persuaded by the decision announced in State v. Chappie (1983), 135 Ariz. 281, 660 P. 2d 1208. In the Chappie case, the Arizona Supreme Court, in overruling the lower court’s exclusion of similar expert testimony, concluded at 293, 660 P. 2d at 1220:
“Even assuming that jurors of ordinary education need no expert testimony to enlighten them to the danger of eyewitness identification, the offer of proof indicated that Dr. Loftus’ testimony would have informed the jury that there are many specific variables which affect the accuracy of identification and which apply to the facts of this case.”
In People v. McDonald (1984), 37 Cal. 3d 351, 208 Cal. Rptr. 236, 690 P. 2d 709, the court commented on the knowledge of the jury regarding eyewitness identifications:
“ * * * It is doubtless true that from personal experience and intuition all jurors know that an eyewitness identification can be mistaken, and also know the more obvious factors that can affect its accuracy, such as lighting, distance, and duration. * * *” Id. at 247, 690 P. 2d at 720.
The court concluded, however, that the variables or factors about which psychologists could testify are “ ‘sufficiently beyond common experience’ that in appropriate cases expert opinion thereon could at least ‘assist the trier of fact * * *.' ” Id. at 248, 690 P. 2d at 721.
In the case before us, the expert’s testimony could have provided similar information to the jury. Thus, we hold that based upon our analysis of these cases and Evid. R. 702, the expert testimony of an experimental psychologist concerning the variables or factors that may impair the accuracy of a typical eyewitness identification is admissible under Evid. R. 702.
Appellant also contends that the opinion testimony of the expert regarding the accuracy of the specific identification testimony of witnesses in this case is admissible under Evid. R. 702. We disagree. While we find the appellant’s first argument persuasive, we are not convinced that the expert opinion of an experimental psychologist should be admissible regarding the credibility of a particular witness’ identification testimony, absent some special identifiable need for the testimony.6
*132The expert testimony offered in Smith, Downing, Chappie and McDonald regarded factors or variables involved in assessing the reliability of eyewitness testimony generally. The expert was not allowed to testify as to how these factors affected the mental processes of specific witnesses.
These results and the result reached in Sims regarding such testimony are supported by the Advisory Committee Notes to Fed. R. Evid. 702 and the Staff Note to Ohio’s Evid. R. 702 which state, respectively:
“* * * The rule * * * recognizes that an expert on the stand may give a dissertation or exposition of scientific or other principles relevant to the case, leaving the trier of fact to apply them to the facts. ” (Emphasis added.)
“* * * The purpose of a jury is to determine the correctness of the * * * [expert’s] opinions. * * * The jury makes that determination by weighing the testimony, applying the usual test of credibility, finding the presence or absence of facts constituting the hypothesis, and by drawing its own inferences and conclusions from the principles explained. ” (Emphasis added.)
The appellant argues that both the situations accompanying the initial observations and the unusual circumstances surrounding the identification procedures in this case created an atmosphere of suggestibility which might not have been obvious to the jury. Appellant maintains that fairness required the admission of the opinion testimony to balance what might have appeared to the jury as substantial corroborated affirmative identifications. Again, we reject the appellant’s thesis.
The witnesses in this case, as all others, are subject to cross-examination pursuant to Evid. R. 611(B), during which time the defense has the opportunity to point out to the jury any discrepancies and inconsistencies in their testimony. Such cross-examination was ably conducted in this case. In addition, closing argument provides the defense with another opportunity to alert the jury to factors which affect the reliability of the identifications offered at the trial. During closing argument in this case the defense raised the issues of the passage of time, short observations and the inconsistent identifications in evidence, as well as other factors. The jury was capable of assessing these factors. When the trial ended, the jury was properly instructed regarding witness credibility and *133the weighing of eyewitness testimony. This court is convinced that, taken as a whole, these rebuttal opportunities provided the jury with a balanced and fair presentation of the facts surrounding the identification testimony offered.7
In conclusion, we hold that the expert testimony of an experimental psychologist regarding the credibility of the identification testimony of a particular witness is inadmissible under Evid. R. 702, absent a showing that the witness suffers from a mental or physical impairment which would affect the witness’ ability to observe or recall events.
Was the exclusion of the expert’s testimony an abuse of the trial court’s discretion? We answer in the negative. This court held in State v. Williams (1983), 4 Ohio St. 3d 53, syllabus, that the decision whether testimony is relevant and will assist the trier is within the discretion of the trial court. Additionally, under Evid. R. 403(B), the trial court retains discretionary authority to exclude even relevant evidence if that evidence would unduly waste time or confuse the issues at trial.
The trial court rejected the expert’s testimony apparently finding that it would not be an aid to the jury. The trial court stated: “* * * So it’s the Court’s opinion that the jury can make the determination on who to believe and who not to believe, using the tests that I will describe to them, using their common sense, and they do not need an expert to help them do that.”
Those cases which have found exclusion of such testimony to constitute an abuse of discretion differ from the one at bar in that in those cases the only evidence connecting the defendant to the crime was the identification testimony. See Chappie and Downing, supra. Conversely, in Smith, supra, the court held that even where it was error to exclude such expert testimony the error was “harmless” where other uncontroverted or substantial evidence links the defendant to the crime.
We find that the evidence of the defendant’s guilt was based primarily on physical evidence rather than identification testimony. In light of the substantial physical evidence, it cannot be said that “* * * ‘it is more probable than not the [exclusion] affected the verdict.’ ” Smith, supra, at 1107, citing United States v. Rasheed (C.A. 9, 1981), 663 F. 2d 843.
For these reasons, we hold that the trial court’s decision not to allow the expert to testify as to the variables which affect typical eyewitness identification did not constitute an abuse of discretion.
II
During the prosecution’s direct examination of FBI agent Alan T. *134Robillard, regarding his comparative analysis of carpet fibers, the following hypothetical question was posed:
“* * * [N]ow assuming the following facts in addition to all of the observations that you have made to the jury, first of all assume that the carpeting from the defendant’s house and the van were manufactured by J.P. Stevens Company; secondly assume further that only twelve thousand, fifteen yards . . . twelve thousand, fifteen square yards of that particular carpeting was [sic] ever manufactured. I’m referring now to the carpeting that you have just described having come from the van and the roll of carpeting. Assume further that this twelve thousand fifteen square yards of carpeting was [sic] manufactured between May of 1979 and July of 1981. Based upon those facts and those assumptions, what is your opinion based upon a reasonable scientific certainty as to the origin of the fibers found on the bedspread * * *.”
Appellant contends that the trial court erred in permitting the agent’s response as follows:
“My opinion is, it’s extremely likely based on these assumptions that the fibers from the bedspread [blanket] came from Mr. Buell’s carpeting.”
Appellant relies upon this court’s holding in State v. Holt (1969), 17 Ohio St. 2d 81 [46 O.O.2d 408], and asserts that the expert’s opinion regarding the similarity or dissimilarity of these fibers must be based on “reasonable scientific certainty” or “probability” not in terms of only a “likelihood.” This court ruled in Holt, supra, that it was reversible error for an expert to testify that hair samples were “likely” to be from the same source. Even considering Holt, however, we do not agree with appellant’s contention. In the case before us, the expert testified as to an extreme likelihood of similarity. The modification of the word “likely” by the adverb “extremely” makes the phrase “extremely likely” equivalent to the word “probable.” Cf. Boze v. Indus. Comm. (App. 1940), 32 Ohio Law Abs. 238, at 242, where the court ruled that the term “ ‘quite possible’ ” as employed by an expert witness was equivalent to “ ‘probable.’ ” Thus we find this claim of error to be without merit.
Ill
Appellant also seeks reversal of his conviction based on the trial court’s alleged prejudicial error in admitting hearsay testimony regarding a shirt found at the scene where the victim’s body was discovered. Over objection of appellant, Officer Roger Pennell was allowed to testify as follows, regarding a shirt given to him by George Dawson on July 24, 1982:
“[Pennell:] A. He indicated that he understood that we had found some garments alongside of the roadway. I told him that I did. Or that we did . . . our department did . . . and he said, that well, he had found this shirt and . . . along the roadway on the 23rd, the day previous, prior to this; and as a result of that he had taken it home and layed [sic] in one of his wash baskets in the laundryroom.
*135“[Prosecution:] Q. Now did you subsequently obtain State’s Exhibit R from Mr. Dawson?
“[Pennell:] A. Mr. Dawson said that he would proceed to his residence and bring that shirt back and give it to me and within a few minutes he proceeded and went to his residence and came back and had the shirt in hand and I left [sic] him drop it right in a plastic bag and I sealed it and gave him a receipt for it.”
“Hearsay” is defined in Evid. R. 801(C) as:
“* * * [A] statement, other than one made by the declarant while testifying at the trial or hearing, offered in evidence to prove the truth of the matter asserted.”
Unless the hearsay testimony falls within one of the exceptions under Evid. R. 802 or 803, it is inadmissible.
Appellant is correct in his assertion that the foregoing testimony is hearsay and, as such, should not have been allowed at trial. However, we do not agree with appellant that this admission constitutes reversible error, but rather we find this error was harmless.
Crim. R. 52(A) defines harmless error as: “[a]ny error, defect, irregularity, or variance which does not affect substantial rights shall be disregarded.” This court, in State v. Ferguson (1983), 5 Ohio St. 3d 160, 166, at fn. 5, commented regarding the appropriateness of finding harmless error:
“* * * [T]he cases where imposition of harmless error is appropriate must involve either overwhelming evidence of guilt or some other indicia that the error did not contribute to the conviction. * * *”
As noted above, the defendant was convicted in light of the presentation of substantial physical evidence. We are convinced that even if the hearsay testimony were to be eliminated from consideration, sufficient evidence would remain to constitute overwhelming proof of the defendant’s guilt.8 See, also, State v. Williams (1983), 6 Ohio St. 3d 281, paragraph six of the syllabus.
Finding no basis for reversing the trial court’s ruling, we uphold the appellant’s convictions.
IV
Turning next to the sentencing phase of the trial, appellant claims that Ohio’s death penalty statutes are unconstitutional per se and are violative of his rights under the Fifth, Sixth, Eighth and Fourteenth Amendments to the United States Constitution and Sections 2, 9, 10 and 16, Article I of *136the Ohio Constitution. Appellant’s constitutional claims have been subdivided into sixteen issues, and are in part as follows:
(1) The death penalty violates due process because it is not a deterrent and, therefore, does not serve a compelling state interest;
(2) The death penalty constitutes cruel and unusual punishment because it is excessive and more severe than necessary to serve legitimate state interests;
(3) Imposition of the death penalty denies equal protection because it is arbitrarily applied by the prosecutor at the charging phase and because there is disparate geographical distribution of death cases;
(4) R.C. 2929.03 fails to provide a meaningful basis for distinguishing between life and death sentences because the jury is not required to specifically state its reasons for recommending life, or the mitigating factors found;
(6) Ohio’s statutory scheme fails to assure adequate appellate analysis of excessiveness and disproportionality of death sentences;
(7) The death statutes deny due process and are cruel and unusual since they permit a death sentence on guilt found beyond a reasonable doubt rather than beyond all doubt;
(9) R.C. 2929.022, 2929.03 and 2929.04 deny effective assistance of counsel and an impartial jury because (a) the trial is bifurcated;
(15) R.C. 2903.01(B) and 2929.04(A)(7) violate due process and equal protection because they fail to specifically require premeditation and deliberation as the culpable mental state for defendants in a capital case; and
(16) R.C. 2929.03 and 2929.04 violate due process and equal protection in providing harsher treatment of defendants convicted of felony murder than those convicted of premeditated murder.
The foregoing questions were addressed and overruled in State v. Jenkins (1984), 15 Ohio St. 3d 164, certiorari denied (1985), _U.S. _, 87 L. Ed. 2d 643. The remaining issues we address below.
In issue 5 appellant contends that R.C. 2929.03, 2929.04 and 2929.05 fail to require the jury to decide the appropriateness of the death penalty.
Appellant’s argument that the jury does not decide the appropriateness of the death penalty is not well-taken, and ignores the mandate to the jury clearly set forth in R.C. 2929.03. In Ohio, the appropriateness of imposing the death penalty in a given case is determined by weighing the aggravating circumstances against any factors which would serve to mitigate the commission of a crime. Only where it is determined, beyond a reasonable doubt, that the aggravating factors outweigh the mitigating factors may a defendant be sentenced to death. In a case tried before a jury, R.C. 2929.03 assigns this weighing task to both the judge and the jury. Following independent deliberations, the jury and judge are required to come to separate conclusions regarding whether life imprisonment or death is the appropriate sentence in the case.
*137Appellant maintains, however, that because the jury’s deliberations are not memorialized in writing, objective appellate review of appropriateness is not possible. We disagree. As we concluded in Jenkins, supra, at 177, such written findings are not an “indispensible ingredient” in assisting appellate courts in determining whether the death sentence was arbitrarily or capriciously imposed. Additionally, while the jury is not required to do so, pursuant to R.C. 2929.03(F) the trial judge must make specific written findings as to both aggravating and mitigating circumstances including a weight evaluation. As such, these findings serve to enhance the record available upon appellate review. In addition, the statutory requirement that the appellate court make an independent determination of sentence appropriateness is an additional safeguard against arbitrary imposition of the death penalty and is not merely the answer to a constitutional mandate of proportionality review. Issue 5 is not well-taken.
In issue 8 appellant says that the death statutes deny due process and equal protection and are cruel and unusual by requiring proof of only the aggravating factors at the guilt stage thus creating a presumptive bias in favor of the aggravating factors over any mitigating factors, and by not genuinely narrowing the class of felony murders since R.C. 2929.04(A)(7) merely repeats the definition of felony murder.
It is appellant’s contention that requiring proof of only the aggravating factors at the guilt phase creates an unconstitutional bias in favor of these factors at the sentencing phase. We do not agree. First we note that whether Ohio’s sentencing statute is one of many or one of only a few which require proof of the aggravating factors at the guilt stage does not determine its constitutionality. See Jenkins, supra, at 174, and Spaziano v. Florida (1984),_U.S._, 82 L. Ed. 2d 340, 355, where the court ruled that “[t]he Eighth Amendment is not violated every time a State reaches a conclusion different from a majority of its sisters, over how best to administer its criminal laws.” We agree with the court of appeals’ finding that no presumptive bias is created in favor of the aggravating factors by requiring their proof beyond a reasonable doubt in the guilt phase. Whether a sentencing phase is needed at all rests upon this predetermination. Accordingly, this issue is overruled.
The appellant further argues that there is no genuine narrowing of the class of felony murders as is constitutionally required since R.C. 2929.04(A)(7), merely repeats the definition of felony murder. We disagree. As noted by the appellate court, “R.C. § 2929.04(A) narrows the class of felony murders subject to the death penalty by excluding those who commit arson, robbery, burglary or escape, unless they are charged with a different aggravating circumstance.” We find no merit in this contention.
In issues 9(b) and (c) appellant argues that R.C. 2929.022, 2929.03 and 2929.04 deny effective assistance of counsel and an impartial jury because *138the mental examination results are made available to all parties including the judge and jury, and Crim. R. 11(C)(3) encourages guilty pleas by allowing the court to dismiss the specifications only if a guilty plea or plea of no contest is accepted.
As properly noted by the appellate court, the defendant decides whether to expose himself to the risk of potentially incriminating presentence investigations, including mental examinations. There is no constitutional infirmity in providing the defendant with such an option. Additionally, the jury should be privy to all information relevant to its task of deciding whether a defendant should be sentenced to life in prison or whether it should recommend that the defendant be put to death.
Likewise, we reject appellant’s contention that Crim. R. 11(C)(3) may encourage guilty pleas, and thereby a waiver of fundamental rights. Crim. R. 11(C)(3) is applicable only in cases where there has been an accepted plea to the charge and specifications. In this case, there was no plea offered or accepted. Even in cases where a plea has been accepted, Crim. R. 11(C)(3) may provide no advantage at all.
This court held in State v. Nabozny (1978), 54 Ohio St. 2d 195 [8 O.O.3d 181], paragraph one of the syllabus, that:
“The discretion given to the trial judge in Crim. R. 11(C)(3) to dismiss the specifications ‘in the interests of justice’ when the defendant enters a plea of guilty or no contest to the charge of aggravated murder is neither violative of defendant’s constitutional right to equal protection of the laws nor does it coerce the defendant to waive his constitutional right to a jury trial.”
In State v. Weind (1977), 50 Ohio St. 2d 224, at 229 [4 O.O.3d 413], we held that:
“* * * [A] defendant, even if he pleads guilty or no contest, is not assured that any or all of the specifications contained in his indictment will be dismissed, since the court may dismiss such specification in the ‘interests of justice.’ * * *” (Emphasis sic.)
Finally, appellant contends that Crim. R. 11(C)(3) violates the pronouncements of United States v. Jackson (1968), 390 U.S. 570.
In Jackson, the court held that a procedure which permitted a defendant to plead guilty, and thereby avoid a sentence of death, was constitutionally impermissible. Since, in Ohio, a sentence of death is possible whether a defendant pleads to the offense or is found guilty after a trial, Crim. R. 11(C)(3) does not violate Jackson. Thus, we reject this contention of appellant and, accordingly, this issue is overruled.
In issue 10 appellant urges that R.C. 2945.25(C) denies an impartial jury by failing to provide an alternative challenge for cause for any juror irrevocably committed to the death penalty even where there is evidence that mitigation outweighs aggravation.
Relying upon Witherspoon v. Illinois (1968), 391 U.S. 510 [46 O.O.2d 368], this court originally addressed the converse of appellant’s claim in *139Jenkins, supra, at 179. In State v. Rogers (1985), 17 Ohio St. 3d 174, at 177, this court, again, addressed this issue by applying the modified standard of Witherspoon as set forth by the United States Supreme Court in Wainwright v. Witt (1985),_U.S._, 83 L. Ed. 2d 841, to wit:
"* * * [T]he proper standard for determining when a prospective juror in a capital case may be excluded for cause because of his views of capital punishment is whether the juror’s views would prevent or substantially impair the performance of his duties as a juror in accordance with his instructions and oath * * *.”
Although R.C. 2945.25(C) does not provide an alternative challenge for cause for such a juror, R.C. 2945.25(0) would allow, if found appropriate, a challenge for cause in such a case in light of Wainwright. Accordingly, we find appellant’s argument without merit.
In issue 11 appellant contends that R.C. 2929.03(D)(2) fails to provide the jury with adequate guidelines for weighing the aggravating and mitigating circumstances, that the mitigating factors contained in R.C. 2929.04(B)(1) through (6) are unconstitutionally vague, and that R.C. 2929.04(B)(7) does not insure individualized sentencing since it permits consideration of “anything.”
Appellant initially takes exception to the language of R.C. 2929.03(D)(2) which requires the jury to determine whether aggravating circumstances “outweigh” mitigating factors and, if so, to recommend death. He contends that the use of the word “outweigh” implies a lesser standard of proof, i.e., preponderance of the evidence. There is no merit to this challenge as the same paragraph of the statute explicitly requires the jury to find “by proof beyond a reasonable doubt” that the aggravating circumstances outweigh the mitigating ones. Absent such a showing, the jury must recommend a life sentence.
Next, in support of his contention regarding the lack of adequate guidelines, appellant unfavorably compares Ohio sentencing statutes to Florida’s, and contends that although Florida’s sentencing system withstood constitutional challenge in Barclay v. Florida (1983), 463 U.S. 939, it did so only because Florida has provided the jury with directives regarding the weighing process in its case law. The Florida statute provides in part:
“(2) Advisory sentence by the jury.— After hearing all the evidence, the jury shall deliberate and render an advisory sentence to the court, based upon the following matters:
“(a) Whether sufficient aggravating circumstances exist as enumerated in subsection (5);
“(b) Whether sufficient mitigating circumstances exist which outweigh the aggravating circumstances found to exist; and
“(c) Based on these considerations, whether the defendant should be sentenced to life imprisonment or death.” Fla. Stat. Ann. 921.141(2) (1985).
*140R.C. 2929.03(D)(2) reads in part:
“Upon consideration of the relevant evidence raised at trial, the testimony, other evidence, statement of the offender, arguments of counsel, and, if applicable, the reports submitted pursuant to division (D)(1) of this section, the trial jury, if the offender was tried by a jury, shall determine whether the aggravating circumstances the offender was found guilty of committing are sufficient to outweigh the mitigating factors present in the case. If the trial jury unanimously finds, by proof beyond a reasonable doubt, that the aggravating circumstances the offender was found guilty of committing outweigh the mitigating factors, the trial jury shall recommend to the court that the sentence of death be imposed on the offender. Absent such a finding, the jury shall recommend that the offender be sentenced to life imprisonment with parole eligibility after serving twenty full years of imprisonment or to life imprisonment with parole eligibility after serving thirty full years of imprisonment.”
We see no real difference in the statutes or in the tasks they impose upon the jury and appellant fails to demonstrate his point by presenting any supporting case law.
In fact, when addressing the guidelines issue regarding the weighing process under Florida law in Proffitt v. Florida (1976), 428 U.S. 242, the United States Supreme Court stated at 258:
“The directions given to judge and jury by the Florida statute are sufficiently clear and precise to enable the various aggravating circumstances to be weighed against the mitigating ones.”
We think this is equally applicable to the Ohio law.
Additionally, in assessing the constitutionality of Florida’s statute in light of the requirement of Furman v. Georgia (1972), 408 U.S. 238, the court in Proffitt also stated at 258:
“* * * While the various factors to be considered by the sentencing authorities do not have numerical weights assigned to them, the requirements of Furman are satisfied when the sentencing authority’s discretion is guided and channeled by requiring examination of specific factors that argue in favor of or against imposition of the death penalty, thus eliminating total arbitrariness and capriciousness in its imposition.
“* * * [T]he trial court’s sentencing discretion is guided and channeled by a system that focuses on the circumstances of each individual homicide and individual defendant in deciding whether the death penalty is to be imposed.” See, also, Jenkins, supra, at 171-173.
Since the jury is required to evaluate specific factors and weigh them in like fashion in this state, the requirements of Furman are equally met by the Ohio law.
Appellant’s next contention is that the absence of definitions renders R.C. 2929.04(B)(1) through (6) unconstitutionally vague. We disagree. These factors, set out as they are in short narratives, are explicit enough to require no further illumination.
*141We also reject appellant’s contention that R.C 2929.04(B)(7) does not insure individualized sentences. Although the sentencing authority can consider “other factors,” these factors are limited to those “that are relevant to the issue of whether the [individual] offender should be sentenced to death.” This so-called “catchall” is in furtherance of R.C. 2929.04(C) which is to provide the defendant with great latitude in presenting evidence of any relevant mitigating factors.
In issue 12 appellant says that R.C. 2929.03, 2929.04 and 2929.05 are unconstitutional because they permit the imposition of the death penalty despite the existence of mitigating circumstances.
First, we note that in this case the defendant failed to present to the court any circumstances which mitigated his actions, and none were found. In addition, as noted above, Florida’s statutes have passed constitutional muster even though they allow the sentencer to recommend death where mitigating circumstances exist, provided they are outweighed by aggravating factors. See Barclay, supra, and Proffitt, supra. The determination in Ohio is the same. This issue is overruled.
In issue 13 appellant argues that R.C. 2929.03, 2929.04 and 2929.05 are unconstitutional because there is no option to recommend life when there are no mitigating circumstances.
While we agree with appellant that mandatory death sentences are unconstitutional, Woodson v. North Carolina (1976), 428 U.S. 280, we reject the appellant’s argument that Barclay must be read to imply that the jury must always have a life option even when no mitigating factors exist. In fact, the life sentence recommended by the jury was rejected by the court in Barclay in the absence of factors in mitigation of the crime. Again, the similarity of the Florida and Ohio statutes causes us to join the appellate court in overruling this contention.
In issue 14 appellant maintains that the specification in the first two counts of appellant’s indictments are unconstitutionally overbroad and vague and are violative of equal protection since kidnapping is inherent in any aggravated murder, are double jeopardy since appellant’s single act both convicts and aggravates, and that the statutes do not make mitigating factors available to one who pleads not guilty.
We disagree with the appellant’s contention that kidnapping is inherent in any aggravated murder and, as such, the murder charges and their specifications relate to but a single act. In State v. Moss (1982), 69 Ohio St. 2d 515 [23 O.O.3d 447], this court construed R.C. 2941.25, the state’s multiple-count statute, and stated at 519:
“The General Assembly then has authorized trial courts, in a single criminal proceeding, to convict and to sentence a defendant for two or more offenses, having as their genesis the same criminal conduct or transaction, provided that the offenses (1) were not allied and of similar import, (2) were committed separately or (3) were committed with a separate animus as to each offense. * * *”
*142In State v. Logan (1979), 60 Ohio St. 2d 126 [14 O.O.3d 373], this court stated:
“* * * [I]n order for two crimes to constitute allied offenses of similar import, there must be a recognized similarity between the elements of the crimes committed [and] [t]he offenses and their elements must correspond to such a degree that commission of the one offense will result in the commission of the other. ” (Emphasis added.)
The significant movement and restraint of the victim in this case was not intrinsic to her murder. Appellant’s abduction and restraint of Krista was more than a mere incidental feature of his murdering her and constituted a separate and distinct act which aggravated the circumstances of her death. Additionally, and contrary to appellant’s contention, the kidnapping specifications to the murder counts do narrow the class of those eligible for the death penalty in that they require additional behavior on the part of the offender subject to death. See, also, Jurek v. Texas (1976), 428 U.S. 262, where the court upheld a Texas statute providing for death for the commission of murder during a kidnapping.
Appellant also maintains that since mitigating factors relate only to the commission of a crime, a person pleading not guilty is denied due process since there are no mitigating factors to be asserted. However, R.C. 2929.04(B)(7) and (C) allow any defendant the opportunity to offer any factors that are relevant to the imposition of the death sentence, and accord the defendant great latitude in doing so.
The proclamation of innocence is a factor relevant to the issue of whether the sentence of death should be imposed and as such can be asserted by a defendant along with any other relevant factors.
This contention is also overruled.
V
Having addressed those constitutional issues raised by the appellant, sua sponte we examine the constitutionality of the imposition of the death penalty in this case in light of the Supreme Court’s recent decision in Caldwell v. Mississippi (1985),_U.S._, 86 L. Ed. 2d 231.
In Caldwell, the petitioner killed the owner of a small grocery store in the course of a robbery and was convicted of capital murder. During the sentencing phase of the trial, petitioner’s lawyer made an impassioned plea for mercy, stressing to the jurors the awesome nature of their life or death decision. In rebuttal, the prosecutor sought to diminish the jurors’ sense of responsibility by assuring them that their decision was not final because it was automatically reviewable by the state’s Supreme Court. The prosecutor’s remarks were buttressed by comments from the trial judge regarding the reviewable nature of the jury’s verdict. The jury sentenced the petitioner to death.
*143On appeal, the Mississippi Supreme Court unanimously affirmed the conviction but upheld the sentence of death by only a four to four vote. Caldwell v. State (Miss. 1983), 443 So. 2d 806. Rejecting petitioner’s argument that the prosecutor’s remarks violated the Eighth Amendment, the prevailing opinion of that court, on authority of California v. Ramos (1983), 463 U.S. 992, was that: “[S]tates may decide whether it is error to mention to jurors the matter of appellate review * * *.” Caldwell v. State, swpra, at 813.
In vacating the death penalty, the United States Supreme Court held that:
“* * * [I]t is constitutionally impermissible to rest a death sentence on a determination made by a sentencer who has been led to believe, as the jury was in this case, that the responsibility for determining the appropriateness of the defendant’s death rests elsewhere.” Caldwell v. Mississippi, supra, at 239.
The court, at 239, quoting Ramos, supra, at 998-999, reiterated that under the Eighth Amendment “* * * ‘the qualitative difference of death from all other punishments requires a correspondingly greater degree of scrutiny of the capital sentencing determination.’ ”
Continuing, at 240, the court said that: “* * * the Eighth Amendment’s ‘need for reliability in the determination that death is the appropriate punishment in a specific case’ ” can only be met where there is assurance that the sentencers treat their power to determine the appropriateness of death as an “awesome responsibility.” (Quoting Woodson v. North Carolina, supra, at 305.)
The court concluded at 244 that the inaccurate and misleading statements of the prosecutor violated the defendant’s constitutional rights because the statements “* * * urged the jurors to view themselves as taking only a preliminary step toward the actual determination of the appropriateness of death — a determination which would eventually be made by others and for which the jury was not responsible. * * *”
Although the effects of the prosecutorial remarks were held, by the United States Supreme Court, to be unconstitutional in Caldwell, Justice O’Connor noted in her concurring opinion at 248 that Ramos, relied upon by the other four justices in the plurality, does not “suggest that the Federal Constitution prohibits the giving of accurate instructions regarding postsentencing procedures.”
In the case at bar, the following instructions to the jury regarding their role in the sentencing process are relevant:
“A jury recommendation to the Court that the death penalty be imposed is just that. A recommendation. And it is not binding upon the Court. The final decision as to whether the defendant will be sentenced to death or to life imprisonment will be made by me, the Judge, after following the procedure and applying the criteria set forth in the statutes.”
Initially we noted that while the jury has the power to impose the *144sentence of death under the Mississippi statute,9 R.C. 2929.08(D)(3) delegates the death sentencing responsibility to the trial court upon its separate and independent finding that the aggravating factors outweigh the mitigating factors in this case. The appellant herein has not alleged, nor does the record in any way reflect, that the trial court was unmindful of the awesome nature of its responsibility in imposing the death penalty.
Secondly, as noted in Part III, supra, Ohio’s multi-leveled appellate review of the trial court’s written findings justifying imposition of death serve as an additional safeguard against capriciousness or unjust bias.
Finally, unlike the comments to the jury in Caldwell v. State, supra, the instructions given to the jury in this case are an accurate statement of the law in Ohio. R.C. 2929.03(D)(2) provides:
“* * * If the trial jury unanimously finds, by proof beyond a reasonable doubt, that the aggravating circumstances the offender,, was found guilty of committing outweigh the mitigating factors, the trial jury shall recommend to the court that the sentence of death be imposed on the offender. * * *” (Emphasis added.)
As we stated in Jenkins, supra, at 202, and we now emphatically emphasize, the better procedure would be to have no comment by the prosecutor or by the trial judge on the question of who bears the ultimate responsibility for determining the penalty. Nevertheless, in the case at bar, the charge of the trial court was not inaccurate or misleading, nor was its effect upon the jury constitutionally infirm. Thus, we find that Caldwell v. Mississippi, supra, is clearly distinguishable from the matter now before us.
In conclusion, we find that the death sentence imposed in this case is appropriate in light of the existence of the aggravating circumstances and the absence of any factors in mitigation of this horrible crime. Additionally, we find the sentence of death to be appropriate as it is neither excessive nor disproportionate to the penalty imposed in similar cases. Finally, convinced as we are that the appellant has received objective, impartial and unbiased review on appeal, we affirm both the conviction and the death sentence. Accordingly, the judgment of the court of appeals is affirmed.
Judgment affirmed.
Celebrezze, C.J., Sweeney, Locher and Holmes, JJ., concur. Connors and Wright, JJ., dissent. *145Connors, J., of the Sixth Appellate District, sitting for C. Brown, J.Ohio’s Evid. R. 702 is an exact transcription of the federal rule of the same number. In Downing, supra, at 1229, the court stated:
“Under [federal] Rule 702, ‘an expert can be employed if his testimony will be helpful to the trier of fact in understanding evidence that is simply difficult, [though] not beyond ordinary understanding.’ S. Saltzburg & K. Redden, Federal Rules of Evidence Manual 451 (3d ed. 1982).”
The Advisory Committee Notes to this rule state in part:
“Whether the situation is a proper one for the use of expert testimony is to be determined on the basis of assisting the trier.” (Emphasis added.)
As noted, the Ohio rule contemplates the same "helpfulness” criterion regarding the admissibility of expert testimony and, in addition, views admissibility favorably when such is relevant. See State v. Williams (1983), 4 Ohio St. 3d 53.
The Sims court also held as reflected in paragraph two of the syllabus:
“* * * The expert testimony of an experimental psychologist, on the issue of whether a particular eyewitness was testifying accurately is likewise inadmissible in the absence of any evidence that the witness suffers from a mental or physical impairment which would affect the witness’ ability to observe or recall events.” (Emphasis added.)
It was the Sims court’s conclusion at 325 that:
*132“There are numerous decisions by American courts in which expert testimony regarding the credibility of witnesses has been received. * * * All of these cases, however, involved allegations that the witness suffered from an organic illness, a psychiatric disorder, or a mental impairment, which would diminish the witness’ ability to accurately perceive, remember, or relate the events testified to. * * *”
The court further concluded at 326:
“The appellant cites no authority which stands for the proposition that expert testimony is admissible on the issue of the ability of a mentally healthy witness of normal intelligence to accurately observe and recall the details of a crime.”
We arrive at the same conclusion. See, also, Annotation (1968), 20 A.L.R. 3d 684, Section 2(a), and Supp. (1985).
As aptly noted by the appellate court, such expert testimony regarding a particular witness’ identification testimony constitutes an attack on the general credibility of the witness by extrinsic evidence of a collateral matter. The introduction of extrinsic evidence to impeach credibility is limited by Evid. R. 608(A) to evidence of one’s character for truthfulness or untruthfulness.
The appellant argues that the shirt, as well as the testimony, should not have been introduced and refers this court to his objection on the grounds of improper foundation. The court properly overruled this objection although we do note that in light of the expert’s testimony that “ ‘no conclusive association could be established between * * * [the defendant’s shirt and the one offered as exhibit R]’ ” there may have been a basis for excluding the shirt on grounds of relevancy. We need not rule on this matter since no such objection was made.
See Miss. Code 1972 Ann. Section 99-19-101(1) and (2) (Supp. 1985). See, also, Williams v. State (Miss. 1984), 445 So. 2d 798, where the Supreme Court of Mississippi stated at 811: “The structure of the capital sentencing system enacted by our Legislature places the entire sentencing burden on the jury. No judge or other official within our system has the power to impose the sentence of death; only the jury.” (Emphasis added.)