[J-17-2020]

IN THE SUPREME COURT OF PENNSYLVANIA

WESTERN DISTRICT

SAYLOR, C.J., BAER, TODD, DONOHUE, DOUGHERTY, WECHT, MUNDY, JJ.

COMMONWEALTH OF PENNSYLVANIA,

Appellee

v.

ROD L. JONES, JR.,

Appellant

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No. 24 WAP 2019

Appeal from the Order of the 

Superior Court entered July 27, 

2018 at No. 1636 WDA 2016, 

affirming in part and vacating in part 

the Judgment of Sentence of the 

Court of Common Pleas of 

Allegheny County entered June 28, 

2016 at No. CP-02-CR-0008782-

2015 and remanding.

SUBMITTED: April 16, 2020

OPINION

JUSTICE MUNDY DECIDED: OCTOBER 30, 2020

In this appeal by allowance, we consider whether opinion testimony from a 

detective concerning the behavior of child victims in response to sexual abuse, informed 

by that detective’s training and experience, constitutes lay or expert testimony under our 

rules of evidence. As a necessary corollary, we also address the continued validity of our 

decision in Commonwealth v. Dunkle, 602 A.2d 830 (Pa. 1992),

1

in light of the 

legislature’s enactment of 42 Pa.C.S. § 5920 (permitting expert testimony concerning

victim behavior in response to sexual abuse in certain criminal proceedings involving 

 

1

In Dunkle, discussed more fully infra, we held inadmissible expert testimony concerning 

typical behavior patterns displayed by child victims of sexual abuse, reasoning it was 

easily understood by laypersons, did not require expert analysis, and invaded the jury’s 

province of determining witness credibility. Dunkle, 602 A.2d at 836-38.
[J-17-2020] - 2

sexual offenses). For the reasons that follow, we reverse the Superior Court’s order and 

remand for a new trial.

I. Facts and Procedural History

Appellant Rod L. Jones, Jr. was charged with rape and various sexual offenses 

following allegations by his stepdaughter (“the victim”) of repeated sexual abuse over a 

period of several years. According to the victim, the first instance of abuse occurred when 

she was thirteen years old. Appellant entered the victim’s bedroom while she was 

sleeping and tried to penetrate her with his penis from behind. The victim pushed 

Appellant away, causing him to leave the room without completing the act. He committed

additional assaults over the next several years, which included performing oral sex on the 

victim, forcing the victim to perform oral sex on him, and also engaging in vaginal 

intercourse. The victim did not tell anyone about these incidents for many years. She 

explained that Appellant told her no one would believe her. The victim also feared what 

Appellant would say about her to her mother. When the victim was seventeen years old, 

she eventually told her mother about the abuse.

On April 5, 2016, Appellant proceeded to a jury trial. Throughout the trial, defense 

counsel focused on discrepancies in the victim’s recounting of events in an attempt to 

undermine her credibility. These discrepancies related to the timing and location of 

certain sexual assaults. At one point, the Commonwealth called as a witness Detective 

Scott Holzwarth, who interviewed the victim during the course of the investigation. The 

Commonwealth began its direct examination by asking Detective Holzwarth the following 

general questions:

[The Commonwealth]: How are you currently employed?

[Detective Holzwarth]: I’m a detective with the Allegheny County 

Police, and I work in the General Investigations Section.
[J-17-2020] - 3

[The Commonwealth]: How long have you been employed in this 

capacity?

[Detective Holzwarth]: Ten years.

[The Commonwealth]: As a detective in the General Investigations 

Unit, do you handle all sorts of crimes or do you have a certain type 

of crime that you do more of?

[Detective Holzwarth]: We do handle different types of crimes, but I 

do mostly crimes against people, which includes sex assaults and 

child abuse.

[The Commonwealth]: And if you could estimate, during the course 

of your career, approximately how many child sexual assault cases 

have you investigated?

[Detective Holzwarth]: Hundreds. I would have to do the math, but 

at least hundreds.

N.T. Trial, 4/6/16, at 97-98. The Commonwealth subsequently asked Detective Holzwarth 

questions specific to his investigation of this matter. Then, particularly relevant to this 

appeal, the following exchange occurred: 

[The Commonwealth]: Did [the victim] indicate whether or not this 

had been going on multiple times?

[Detective Holzwarth]: Yes.

[The Commonwealth]: And in your training and experience, 

Detective, do kids often have trouble remembering each and every 

time when this is an ongoing incident?

[Detective Holzwarth]: Yes, they do. As a matter of fact, in our 

criminal complaints we normally put a little blurb in there that explains 

that victims ̶

[Defense Counsel]: Your Honor, I would object to this as expert 

testimony. This is an opinion.

The Court: I’m going to overrule.

[The Commonwealth]: Please continue, Detective.
[J-17-2020] - 4

[Detective Holzwarth]: ̶ that explains that victims sometimes have 

trouble remembering exact dates when events have happened.

[The Commonwealth]: And have you also found in your training and 

experience with your specific cases whether or not victims will have 

trouble recalling in each incident that they’re assaulted every single 

detail of the assault?

[Detective Holzwarth]: Yes.

[The Commonwealth]: And do they often times get the times that 

those things happened confused with other times that they discuss 

with you?

[Detective Holzwarth]: Yes. Very often.

Id. at 100-101. On cross examination, defense counsel asked Detective Holzwarth if it 

was possible that a victim’s delay in reporting or inability to provide details about sexual 

assault incidents could mean that no abuse occurred in the first instance, to which the 

detective agreed. Id. at 109-110.

The jury ultimately found Appellant guilty of rape, involuntary deviate sexual 

intercourse with a person under sixteen years of age, unlawful contact with a minor, 

aggravated indecent assault, sexual assault, statutory sexual assault, endangering the 

welfare of a child, corruption of minors, and indecent assault of a person under sixteen

years of age.

2

 The trial court sentenced Appellant to an aggregate term of twenty-seven 

to sixty years’ imprisonment. Appellant filed a post-sentence motion, which the trial court 

denied. He then filed a timely notice of appeal to the Superior Court.

On appeal, Appellant argued, inter alia, that the trial court abused its discretion by 

allowing Detective Holzwarth to testify that child sexual assault victims are often unable 

to recall specific details and dates of sexual assaults. Appellant claimed that this evidence 

constituted expert testimony because it was not within the scope of knowledge possessed 

 

2 See 18 Pa.C.S. §§ 3121(a), 3123(a)(7), 6318(a)(1), 3125(a)(1), 3124.1, 3122.1(a)(2), 

4304(a)(1), 6301(a)(1)(ii), and 3126(a)(8), respectively.
[J-17-2020] - 5

by the average layperson, but was rather based on the detective’s specialized training 

and experience concerning child victim responses and behaviors to sexual assault. 

Appellant argued that absent qualification as an expert witness, the trial court should have 

precluded this testimony. 

The trial court issued an opinion pursuant to Pa.R.A.P. 1925(a) addressing

Appellant’s claim that admission of the detective’s testimony was improper. It explained 

that defense counsel’s strategy at trial involved discrediting the victim. In light of these 

repeated attacks, the trial court concluded the Commonwealth “was entitled to question 

Detective Holzwarth regarding his experience with child victims.” Trial Ct. Op., 5/5/17, at 

9. It also recognized that while cross-examining Detective Holzwarth, defense counsel 

“was able to get the [d]etective to concede that an alternative reason the allegations by 

child victims lacked detail was that they never happened.” Id. at 9-10. For this reason, 

the trial court alternatively concluded that any damage resulting from admission of 

Detective Holzwarth’s testimony was remedied by defense counsel’s effective crossexamination. Id. at 10.

The Superior Court affirmed in a divided, unpublished memorandum opinion. 

Commonwealth v. Jones, 1636 WDA 2016, 2018 WL 3598642 (Pa. Super. July 27, 2018). 

The majority explained that challenges to the admissibility of evidence typically rest within 

the sound discretion of the trial court and will not be reversed absent an abuse of

discretion. Id. at *2 (citing Commonwealth v. Maloney, 876 A.2d 1002, 1006 (Pa. Super. 

2005)). It noted that an abuse of discretion “is not merely an error of judgment, but is 

rather the overriding or misapplication of the law, or the exercise of judgment that is 

manifestly unreasonable or the result of bias, prejudice, ill-will or partiality, as shown by 

the evidence or the record.” Id. (citing Commonwealth v. Cameron, 780 A.2d 688, 692 

(Pa. Super. 2001) (citation and quotation omitted)). The majority then recounted the 
[J-17-2020] - 6

language of Pennsylvania Rules of Evidence 701 and 702, which pertain to lay opinion 

and expert witness testimony, respectively. Id. at *2-3.

After reviewing the testimony at issue, the majority concluded that the trial court 

did not abuse its discretion by permitting the detective, without first being qualified as an 

expert witness, to provide opinion testimony about the inability of child victims of sexual 

abuse to recall specific dates and details of sexual assaults. Id. at *4. The majority 

reasoned that such testimony constituted permissible lay opinion testimony because it 

was based on information within the detective’s personal knowledge and experience, in 

light of observations with similar child victims of sexual abuse. Id. It was also helpful to 

the trier of fact and was not based upon scientific, technical, or other specialized 

knowledge. Id. Thus, the Commonwealth was not required to qualify Detective Holzwarth 

as an expert witness in order for him to testify to this information. Id.

Senior Judge Eugene B. Strassburger filed a dissenting opinion which, in relevant 

part, disagreed with the majority’s conclusion that the detective’s testimony constituted

lay opinion testimony. Id. at *8. He recognized that in Dunkle, this Court specifically 

found that testimony concerning the reasons why child victims of sexual abuse delay 

reporting incidents of sexual abuse, omit details regarding sexual abuse, and are unable 

to remember dates and times of instances of sexual abuse was within the understanding 

of lay persons and did not require expert analysis. Id. (citing Dunkle, 602 A.2d at 836-

38). While Dunkle appears dispositive of the instant issue, Judge Strassburger noted that

case predated the legislature’s enactment of 42 Pa.C.S. § 5920, which now authorizes

expert testimony on this subject matter. Id.

Judge Strassburger explained that in Commonwealth v. Olivo, 127 A.3d 769, 780 

(Pa. 2015), this Court described Section 5920 as a substantive rule authorizing experts 

to testify to facts and opinions regarding specific types of victim responses and behaviors.
[J-17-2020] - 7

Id. No court, however, has explicitly addressed whether the enactment of Section 5920 

effectively overruled Dunkle’s holding that opinions regarding responses by child sexual 

assault victims fall within the knowledge of laypersons. Id. (citing Commonwealth v. 

Maconeghy, 171 A.3d 707, 709 n.2 (Pa. 2017) (recognizing that Dunkle is “impacted by 

the enactment of Section 5920[,]” but noting that “specific effect of the statute” was 

beyond the scope of review) (additional citation omitted)). Id. Judge Strassburger opined

that the holding in Dunkle in this regard is no longer valid when viewed alongside Section 

5920, which “classifies such knowledge, when acquired through experience, training, or 

education in criminal justice related to sexual violence, as specialized.” Id. 

Turning to the merits, Judge Strassburger highlighted the majority’s failure to

address Dunkle and Section 5920 or assess whether the detective’s testimony amounted 

to expert testimony under Rule 702. Id. Judge Strassburger explained that contrary to 

the majority’s conclusion, Detective Holzwarth’s testimony concerning victim responses 

following sexual abuse was explicitly based upon his training and experience as one who 

investigates sexual assaults, which falls squarely within the type of expert testimony 

permissible under Section 5920(b)(1). Id. (citing Commonwealth v. Huggins, 68 A.3d 

962, 969 (Pa. Super. 2013) (“[A]n officer testifies as an expert when he brings the wealth 

of his experience as an officer to bear on those observations and makes connections for 

the jury based on that specialized knowledge.”) (citation and quotation omitted); 

Commonwealth v. Powell, 171 A.3d 294, 307 (Pa. Super. 2017) (holding a police officer 

may testify as an expert witness based upon knowledge gained from practical and 

occupational training)). The testimony was therefore impermissible absent any attempt 

by the Commonwealth to qualify Detective Holzwarth as an expert witness. Id. Thus, 

Judge Strassburger concluded that the trial court erred by admitting the testimony and

such an error called for a new trial. Id.
[J-17-2020] - 8

Appellant filed a petition for allowance of appeal. We granted allowance of appeal 

to address the following related issues:

1. Whether testimony from a detective about victim responses and 

behaviors, when based on that detective’s training, experience, and 

specialized knowledge, constitutes expert testimony and whether permitting 

such testimony from a lay witness is inconsistent with the plain language of 

Pa.R.E. 701, Pa.R.E. 702, and Commonwealth v. Huggins, 68 A.3d 962 

(Pa. Super. 2013)?

2. Whether the General Assembly’s enactment of 42 Pa.C.S. § 5920 

(relating to expert testimony in certain criminal proceedings) legislatively 

overruled this Honorable Court’s decision in Commonwealth v. Dunkle, [ ] 

602 A.2d 830 ([Pa.] 1992), which held that specific types of victim responses 

and behaviors are within the range of common experience, easily 

understood by lay people, and for which expert analysis is inappropriate?

Commonwealth v. Jones, 207 A.3d 913 (Pa. 2019) (per curiam).

II. Admissibility of Detective Holzwarth’s Testimony

A. Parties’ Arguments

We now turn to the parties’ arguments concerning the admissibility of the 

detective’s testimony. Appellant argues that testimony from a detective concerning victim 

behavior in response to sexual abuse, when based upon that detective’s training, 

experience, and specialized knowledge as a law enforcement officer, is not permissible 

lay opinion testimony under Rule 701. Appellant’s Brief at 12. Appellant emphasizes that 

lay opinion testimony must be based upon personal knowledge and must not involve 

specialized knowledge within the scope of Rule 702. Id. at 15. Appellant avers that the 

detective’s testimony was not based upon personal knowledge, as it was beyond that 

which an ordinary witness could conclude from observation and “based on nothing more 

than his personal perceptions of [child victims’] reports of alleged abuse.” Id. at 18-19. 

Appellant also argues that the detective’s testimony was based upon specialized 

knowledge gained through experience as a law enforcement officer and therefore falls 

squarely within the realm of expert testimony. Id. at 18-19. For these reasons, Appellant 
[J-17-2020] - 9

argues that Detective Holzwarth’s testimony was inadmissible, absent qualification as an 

expert. Id.

Appellant highlights the distinction between lay and expert testimony by relying on 

Huggins, in which the Superior Court held that Pa.R.E. 701 and 702 “do not preclude a 

single witness from testifying, or offering opinions, in the capacity as both a lay and expert 

witness on matters that may embrace the ultimate issues to be decided by the fact-finder.” 

Id. at 21-22 (quoting Huggins, 68 A.3d at 967). Based on Huggins, Appellant argues that 

“the Commonwealth plainly could have proffered Detective Holzwarth as a dual-capacity 

witness[,]” but instead “evaded the reliability requirements inherent in [Rule] 702 through 

the simple expedient of proffering [him] in lay witness clothing.” Id. 

Appellant further maintains that both this Court and the legislature have recognized 

that testimony concerning victim behavior and responses to sexual abuse, if admissible, 

may only be offered by a properly qualified expert. Id. at 22. He claims that this Court 

has never held testimony concerning victim behavior in response to sexual abuse to be

permissible lay opinion testimony. Id. Appellant also points to the legislature’s passage 

of Section 5920, which explicitly classifies knowledge pertaining to the dynamics of sexual 

violence, victim responses to sexual violence, and the impact of sexual violence on 

victims during and after being assaulted, as expert testimony when gleaned from 

experience with or specialized training related to sexual assault. Id. at 24-25. Finally, 

Appellant asserts that the trial court’s admission of the instant testimony, which had the 

sole effect of improperly bolstering the victim’s credibility, was so prejudicial as to warrant 

a new trial. Id. at 25.

The Commonwealth argues that the detective’s testimony did not constitute expert 

testimony but was rather properly admitted as lay testimony. Commonwealth’s Brief at 

10. It maintains that contrary to expert testimony, the detective relayed information based 
[J-17-2020] - 10

solely upon personal observations rather than reference to any fact, testimony, or 

empirical data that would require it to be proffered as expert testimony. Id. at 13. The 

Commonwealth notes that, although the detective spoke to observations that jurors had 

not experienced in the same manner, his testimony was nonetheless within the realm of 

common understanding and did not intrude into an area reserved for expert testimony. 

Id. The Commonwealth further asserts that the detective’s status as a law enforcement 

officer did not preclude him from offering lay opinion testimony. Id. at 14 (citing Huggins, 

68 A.3d at 967). 

The Commonwealth also disagrees with Appellant’s contention that the instant 

testimony rose to the level of expert testimony simply because the detective was asked 

about training and experience as a police officer prior to providing a response. Id. at 15. 

It submits that “merely framing a question with the words training and experience does 

not elevate the resulting answers to expert testimony.” Id. at 17. The Commonwealth 

asserts that the detective’s testimony, which merely stated general observations that child 

victims of sexual assault confuse dates and have trouble recalling every detail of 

incidents, was a common sense observation capable of being understood by the average 

person. Id. at 17-18 (citing Dunkle, 602 A.3d at 836-38).

The Commonwealth further maintains that even if the detective’s testimony 

constituted expert testimony, its admission did not result in prejudice that would require 

reversal. Id. at 21 (citing Commonwealth v. Fulton, 179 A.3d 475, 493 (Pa. 2018)). It 

explains that while the detective stated child victims of sexual abuse often forget dates 

and details of incidents, he alternatively acknowledged on cross-examination that 

confusion regarding these facts may also mean an assault did not occur. Id. at 22. 

Furthermore, the Commonwealth argues that despite defense counsel’s repeated 

attempts to undermine the victim’s credibility, the detective never rendered an opinion as 
[J-17-2020] - 11

to whether or not the victim in this case was telling the truth. Id. Thus, admission of the 

testimony was harmless. Id. at 23. 

B. Analysis

An appellate court generally reviews a trial court’s decisions regarding the 

admissibility of evidence for an abuse of discretion. Commonwealth v. Johnson, 42 A.3d 

1017, 1027 (Pa. 2012) (“An abuse of discretion may not be found merely because an 

appellate court might have reached a different conclusion, but requires a result of 

manifest unreasonableness, or partiality, prejudice, bias, or ill-will, or such a lack of 

support so as to be clearly erroneous.”) (citations and quotations omitted). This case

additionally requires us to examine the proper interpretation of our rules of evidence, a 

question of law for which our standard of review is de novo and our scope of review is 

plenary. Commonwealth v. Brown, 52 A.3d 1139, 1176 (Pa. 2012). When interpreting 

our rules of evidence, we must ascribe to the words of these rules their plain and ordinary 

meaning. Id. (citation omitted). 

Whether Detective Holzwarth’s testimony, predicated on his knowledge and 

experience as a police officer, was properly admitted as lay opinion testimony requires 

an examination of two relevant Pennsylvania Rules of Evidence. Rule 701 permits lay 

witnesses to provide opinion testimony only if such testimony meets three limiting criteria:

Pa.R.E. 701. Opinion Testimony by Lay Witnesses

If a witness is not testifying as an expert, testimony in the form of an opinion 

is limited to one that is: 

(a) rationally based on the witness’s perception;

(b) helpful to clearly understanding the witness’s testimony or 

determining a fact in issue; and

(c) not based on scientific, technical, or other specialized knowledge 

within the scope of Rule 702.
[J-17-2020] - 12

Pa.R.E. 701. The first and second criteria outlined in the rule are self-explanatory, in that 

they simply require that a witness’s opinion testimony be based upon personal knowledge 

and be helpful to the jury in understanding the witness’s testimony or a fact at issue. The 

final limiting criteria precludes lay witness opinion testimony based upon scientific, 

technical, or other specialized knowledge that falls within the realm of expert opinion 

testimony as outlined by Rule 702, which provides as follows:

Pa.R.E. 702. Testimony by Expert Witnesses

A witness who is qualified as an expert by knowledge, skill, experience, 

training, or education may testify in the form of an opinion or otherwise if:

(a) the expert’s scientific, technical, or other specialized knowledge 

is beyond that possessed by the average layperson;

(b) the expert’s scientific, technical, or other specialized knowledge 

will help the trier of fact to understand the evidence or to determine 

a fact in issue; and

(c) the expert’s methodology is generally accepted in the relevant 

field. 

Pa.R.E. 702. We have explained that “[e]xpert testimony is permitted only as an aid to 

the jury when the subject matter is distinctly related to a science, skill, or occupation 

beyond the knowledge or experience of the average layman.” Commonwealth v. Duffey, 

548 A.2d 1178, 1186 (Pa. 1988) (citation omitted). We have also recognized that the 

standard for qualifying as an expert is a liberal one and the witness need only have “‘any 

reasonable pretension to specialized knowledge on the subject matter under 

investigation’” and the weight to be given to the expert’s testimony is for the factfinder. 

Commonwealth v. Gonzales, 546 A.2d 26, 31 (Pa. 1988) (quoting Kuisis v. Baldwin-LimaHamilton Corp., 319 A.2d 914, 924 (Pa. 1974) (additional citation omitted)); see also

Comment, Pa.R.E. 702. We have also noted that “[e]xpertise, whether acquired as a 
[J-17-2020] - 13

result of formal education or by experience, is expertise.” Commonwealth v. Auker, 681 

A.3d 1305, 1317 (Pa. 1996).

We conclude that the opinion testimony by Detective Holzwarth on the inability of 

child victims of sexual abuse to recall specific dates and details was based upon scientific, 

technical, or other specialized knowledge within the scope of Rule 702. Specifically, 

Detective Holzwarth based his testimony on his training and experience investigating 

sexual assaults. Nevertheless, this did not require Detective Holzwarth to testify solely 

as an expert. The Superior Court’s decision in Huggins is helpful in this regard. 

In Huggins, the Superior Court considered whether Rules 701 and 702 precluded 

a police officer from testifying as both a lay and expert witness. Huggins, 68 A.3d at 966, 

974. The court ultimately held that the plain language of these rules “do not preclude a 

single witness from testifying, or offering opinions, in the capacity as both a lay and expert 

witness on matters that may embrace the ultimate issues to be decided by the factfinder[,]” so long as the jury is properly instructed to avoid confusion. Id. at 967, 974. In 

reaching this conclusion, the panel referenced federal case law highlighting the difficulty 

in distinguishing between an officer’s lay and expert testimony:

We have explained that [a] law enforcement officer’s testimony is lay 

opinion if it is limited to what he observed . . . or to other facts derived 

exclusively from [a] particular investigation . . . . On the other hand, an

officer testifies as an expert when he brings the wealth of his experience as 

[an] officer to bear on those observations and [makes] connections for the 

jury based on that specialized knowledge.

Id. at 969 (quoting United States v. Christian, 673 F.3d 702, 709 (7th Cir. 2012) (additional 

quotations and citations omitted)). The panel also acknowledged that distinguishing 

between an officer’s expert and lay testimony “is often far from clear” when that officer 

possesses specialized knowledge and was also personally involved in the facts 

underlying the case. Id. It explained that “‘[t]he inferences officers draw when observing 

and responding to situations cannot always be separated from the expertise they bring to 
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evaluate those situations. Their observations are guided by experience and training and 

thus, at least some of their fact testimony will be influenced by specialized knowledge.’” 

Id. (quoting Christian, 673 F.3d at 708). 

In light of Huggins, we agree with Appellant that the Superior Court erred in 

concluding that the instant testimony was admissible as lay opinion because it did not 

involve specialized knowledge within the realm of expert testimony. Here, Detective 

Holzwarth primarily functioned as a fact witness but was also called upon to offer general 

opinion testimony concerning whether or not it was common for child victims of sexual 

assault to have trouble remembering dates and details of ongoing sexual assaults. 

Detective Holzwarth was asked to provide insights gained through specialized 

occupational training and experience not within the average layperson’s knowledge base

as required by the plain language of Rule 702(a). Detective Holzwarth called upon the 

wealth of his knowledge and training as a detective with extensive experience 

investigating sexual assaults and made connections for the jury based on that specialized 

knowledge. While some laypersons may be aware of common behaviors and responses 

to sexual abuse, it would be a generalization to assume that the average juror is privy to 

the complex psychological dynamics surrounding sexual abuse. Accordingly, we hold 

that testimony from a law enforcement officer concerning child victims’ typical behaviors 

and responses to sexual abuse, when based on that officer’s training and experience,

falls within the realm of expert testimony. Moreover, as detailed above, Section 5920 

specifically provides that such testimony is an appropriate topic for expert analysis.

3

 We 

 

3 We recognize that this conclusion conflicts with Dunkle insofar as that case can be read 

as precluding entirely expert testimony concerning facts and opinions regarding specific 

types of victim responses and behaviors to sexual abuse. We consider the continued 

validity of Dunkle in this regard below, as well as the impact of Section 5920 on its holding.
[J-17-2020] - 15

further emphasize that whether expert testimony on this topic is admissible is subject to 

all other admissibility concerns, such as proper qualification as an expert.4 

We must now consider the appropriate remedy given the improper admission of 

this testimony. This Court has held that an error may be considered harmless “only if the 

appellate court is convinced beyond a reasonable doubt that the error is harmless.” 

Commonwealth v. Story, 383 A.2d 155, 162 (Pa. 1978). “[A]n error cannot be held 

harmless unless the appellate court determined that the error could not have contributed 

to the verdict. Whenever there is a reasonable probability that an error might have 

contributed to the conviction, the error is not harmless.” Id. at 164. In Story, this Court 

outlined three scenarios under which an error may be deemed harmless, which have

been summarized in subsequent cases as follows: 

Harmless error exists if the state proves either: (1) the error did not prejudice 

the defendant or the prejudice was de minimis; or (2) the erroneously 

admitted evidence was merely cumulative of other untainted evidence 

which was substantially similar to the erroneously admitted evidence; or (3) 

the properly admitted and uncontradicted evidence of guilt was so 

overwhelming and the prejudicial effect of the error was so insignificant by 

comparison that the error could not have contributed to the verdict.

Commonwealth v. Fulton, 179 A.3d 475, 493 (Pa. 2018) (additional citations omitted).

This case implicates the first analytical approach, as it involves the impact of the 

detective’s improperly admitted testimony. We disagree with the Commonwealth that 

admission of the instant testimony was harmless. This case involved competing 

narratives about whether or not various sexual assaults occurred, making credibility a 

central issue. Whether intentional or unintentional, the Commonwealth’s emphasis on 

 

4 The Commonwealth’s framing of its questions in terms of training and experience 

significantly impacts our decision in this case. By doing so, the Commonwealth signaled 

the imprimatur of the detective to provide generalized expert testimony regarding 

behavior patterns of child victims of sexual abuse. We note, however, that testimony from 

the detective based solely on factual observations, without extrapolation to victim 

behavior generally, would arguably be admissible as lay opinion testimony, as it does not 

signal any type of specialized knowledge.
[J-17-2020] - 16

Detective Holzwarth’s training and experience prior to eliciting testimony concerning 

common victim behavior in response to sexual abuse likely signaled to the jury that he

was qualified to offer such a response. As a result, the jury was able to draw an inference 

that the victim’s behavior in this case was consistent with similarly situated victims, 

without any of the heightened reliability concerns that accompany expert testimony. We 

therefore cannot say with certainty that the jury did not place undue weight on the 

testimony, despite defense counsel’s attempt to neutralize the effect of the testimony on 

cross-examination by eliciting a concession from the detective that an inability to recall 

dates and times of assaults could mean no assault occurred. Appellant is therefore

entitled to a new trial.

III. Commonwealth v. Dunkle and 42 Pa.C.S. § 5920

Before proceeding to the next issue, we find it necessary to recount our decision 

in Dunkle, as well as the statutory language of Section 5920.5 In Dunkle, this Court 

addressed, inter alia, whether it was error to admit expert testimony explaining why 

sexually abused children may be unable to recall details of assaults, omit details of 

assaults, and delay reporting assaults. Dunkle, 602 A.2d at 831. We concluded that such 

testimony was “easily understood by lay people and did not require expert analysis.” Id.

at 836-838. We additionally found that testimony on this topic invaded the jury’s sole 

province of determining witness credibility. Id. at 837-38 (citing Commonwealth v. Seese, 

 

5 The Commonwealth asserts that Appellant waived any claim concerning the validity of 

Dunkle in light of the legislature’s passage of Section 5920 by failing to raise it in the 

courts below. Commonwealth’s Brief at 24. We decline to find this issue waived, but 

rather subsumed by the scope of our grant of allocatur. 
[J-17-2020] - 17

517 A.2d 920 (Pa. 1986) (holding inadmissible expert testimony concerning veracity of 

child victim in sexual abuse case) (additional citations omitted)).6

More than twenty years following our decision in Dunkle, the legislature enacted 

Section 5920, which provides as follows:

§ 5920. Expert testimony in certain criminal proceedings

(a) Scope. ̶This section applies to all of the following:

(1) A criminal proceeding for an offense for which registration is 

required under Subchapter H of Chapter 97 (relating to registration 

of sexual offenders).

(2) A criminal proceeding for an offense under 18 Pa.C.S. [Chapter] 

31 (relating to sexual offenses).

(b) Qualifications and use of experts. ̶

(1) In a criminal proceeding subject to this section, a witness may be 

qualified by the court as an expert if the witness has specialized 

knowledge beyond that possessed by the average layperson based 

on the witness’s experience with, or specialized training or education 

in, criminal justice, behavioral sciences or victim services issues, 

related to sexual violence, that will assist the trier of fact in 

understanding the dynamics of sexual violence, victim responses to 

sexual violence and the impact of sexual violence on victims during 

and after being assaulted.

(2) If qualified as an expert, the witness may testify to facts and 

opinions regarding specific types of victim responses and victim 

behaviors.

 

6

In Dunkle, we also considered whether the trial court erred by allowing expert testimony 

concerning behavior patterns of child sexual assault victims, referred to then as “child 

sexual abuse syndrome.” Dunkle, 602 A.2d at 832. We concluded that based upon 

research available at the time, expert testimony on this topic should have been precluded 

as it was not “sufficiently established to have gained general acceptance in the particular 

field in which it belongs[,]” for purposes of the test set forth in Frye v. United States, 293 

F. 1013 (D.C. Cir. 1923). Id. at 834 (citation omitted). This aspect of our holding in Dunkle

is not relevant to the instant appeal, as this case does not involve testimony concerning 

child sexual abuse syndrome.
[J-17-2020] - 18

(3) The witness’s opinion regarding the credibility of any other 

witness, including the victim, shall not be admissible.

(4) A witness qualified by the court as an expert under this section 

may be called by the attorney for the Commonwealth or the 

defendant to provide the expert testimony. 

42 Pa.C.S. § 5920.

IV. Continued Validity of Dunkle in light of 42 Pa.C.S § 5920

A. Parties’ Arguments

We now turn to the parties’ arguments concerning the continued validity of Dunkle

in light of Section 5920. Appellant first notes that the doctrine of separation of powers 

prohibits the legislature from overruling this Court’s judicial decisions through acts of 

assembly. Appellant’s Brief at 27 (citing Leahey v. Farrell, 66 A.2d 577, 579 (Pa. 1949)).

Turning to Olivo, Appellant recognizes that we narrowly held Section 5920 did not infringe

on our constitutional authority to govern the procedure of the courts. Id. at 28-29 (citing 

Olivo, 127 A.3d at 769). He asserts that this decision, however, does not preclude us 

from concluding that certain other applications of Section 5920 are impermissible. 

Specifically, Appellant argues Section 5920 must be construed in a manner consistent 

with Dunkle and our longstanding precedent prohibiting expert testimony that invades the 

jury’s province to determine witness credibility. Id. at 28-30 (citing Commonwealth v. 

Alicia, 92 A.3d 753, 760 (Pa. 2014); Maconeghy, 171 A.3d at 712). 

With respect to whether the statute offends this prohibition, Appellant asserts that 

although Section 5920 expressly precludes expert witness opinions concerning the 

credibility of witnesses, including the victim, the statute nonetheless cannot be reconciled 

with decisions of this Court. Id. at 33. In Appellant’s view, Section 5920 is particularly at 

odds with Dunkle and Commonwealth v. Balodis, 747 A.2d 341 (Pa. 2000), insofar as it 

permits a properly qualified expert to testify to facts and opinions concerning types of 

victim behaviors. Id. at 33. He explains that in Dunkle, we concluded that expert 
[J-17-2020] - 19

testimony concerning typical behavior patterns displayed by child victims of sexual abuse 

invaded the jury’s province of determining witness credibility. Id. at 33-36 (citing Dunkle, 

602 A.2d at 837-38). He further notes that in Balodis, we found that counsel rendered 

ineffective assistance by failing to preserve a challenge to the trial court’s admission of 

expert testimony which bolstered the credibility of victim in child sexual assault case. Id. 

at 36-37 (citing Balodis, 747 A.2d at 344-48).

Appellant again discusses our decision in Olivo, and interprets our holding as a 

“wholesale rejection” of the argument that Section 5920 contravenes our decision in 

Dunkle, and asks us to revisit that conclusion. Id. at 38. He argues that Dunkle plainly 

found expert testimony concerning why sexually abused children omit details of assaults, 

cannot recall details of assaults, or delay reporting of assaults invaded the jury’s province 

as sole arbiter of credibility. Id. at 41 (Dunkle, 602 A.2d at 836-38). He asserts that this 

conclusion was distinct from our finding that expert testimony concerning the uniformity 

of behavior generally displayed by child victims of sexual assault did not meet the Frye

standard for admitting expert testimony. Id. at 42. For this reason, Appellant argues that 

any advancements in science pertaining to this subject matter would be an illegitimate 

basis to reject our holding in Dunkle. Id. at 43. Appellant lastly observes that our 

precedent precluding expert testimony touching upon witness credibility is “inextricably 

linked” to due process rights, as well as the right to trial by an impartial jury. Id. He argues 

that because Section 5920 touches upon the constitutional rights of criminal defendants 

by permitting expert testimony in a manner that invades the jury’s role of determining

credibility, the legislature exceeded its authority by enacting the statute. Id. at 43-44.7

 

7 The Defender Association of Philadelphia and the Pennsylvania Association of Criminal 

Defense Lawyers filed an amicus brief in support of Appellant. They do not offer any 

argument as to whether the testimony at issue constitutes expert or lay testimony, but 

instead focus on the second issue, largely echoing the arguments made by Appellant. 
[J-17-2020] - 20

Notwithstanding its waiver argument, the Commonwealth agrees with Appellant 

that the legislature may not overrule our judicial decisions. Commonwealth’s Brief at 28. 

It further maintains that our decisions in both Olivo and Maconeghy indicate that Section 

5920 alters the interpretation of Dunkle. Id. at 28-31. The Commonwealth submits that 

the premise in Dunkle that certain victim responses and behaviors are capable of being 

understood by laypersons remains valid and urges us to view Section 5920 as “creating 

a means, under the appropriate circumstances, to permit expert testimony with regard to 

specific victim responses and behaviors[.]” Id. at 33. 

The Commonwealth explains that by enacting Section 5920, the legislature 

acknowledged that expert testimony concerning certain types of victim responses and 

behaviors are indeed beyond the common knowledge of laypersons, aligning 

Pennsylvania with the prevailing view among all other states. Id. at 34-37. The 

Commonwealth then references this Court’s decision in Commonwealth v. Walker, 92 

A.3d 766 (Pa. 2014), which concerned the admission of expert testimony on the topic of 

eyewitness identification, to illustrate that scientific developments in a certain field may 

alter courts’ evidentiary determinations. Id. at 38. Accordingly, the Commonwealth avers 

that Dunkle is outmoded in that it concludes all responses and behaviors are within the 

realm of knowledge possessed by laypersons. Id. at 39. In this regard, the 

Commonwealth disagrees with Appellant that scientific progress is an inappropriate basis 

to reject our holding in Dunkle. Id. at 38. 

Finally, the Commonwealth further disagrees with Appellant that Section 5920 

impermissibly intrudes on the jury’s role of determining credibility. Id. It explains that our 

decision in Olivo acknowledged that the holding in Dunkle was partly based on thenavailable research, therefore its conclusion that testimony concerning victim responses 

and behaviors was “based, at least partially, on its assumption that the jury was already 
[J-17-2020] - 21

well equipped to understand these matters.” Id. at 40. It again references Walker, this 

time to support its assertion that testimony concerning victim behavior in response to 

sexual abuse does not infringe upon the jury’s credibility determinations. Id. at 41. There, 

this Court concluded that expert testimony on psychological factors that may influence 

eyewitness identification did not speak to witness credibility, but “provide[d] jurors with 

education by which they assess themselves the witness’s credibility.” Id. (quoting Walker, 

92 A.3d at 784). As for the scope and parameters of expert testimony concerning victim 

responses and behaviors, the Commonwealth points out that Section 5920 merely speaks 

to the relevancy of the expert’s testimony, while the proponent of the testimony must still 

prove the testimony meets the admissibility standards set forth in Frye. Id. at 46-47 (citing 

Commonwealth v. Cramer, 195 A.3d 594 (Pa. Super 2018)). 

B. Analysis

Whether the legislature’s enactment of Section 5920, which allows for expert 

testimony concerning victim behavior in response to sexual abuse in certain criminal 

proceedings involving sexual offenses, effectively overruled our decision in Dunkle poses

a question of law, for which our standard of review is de novo and our scope of review is 

plenary. Commonwealth v. Martinez, 147 A.3d 517, 529 (Pa. 2016) (citing

Commonwealth v. Crawley, 924 A.2d 612, 614 (Pa. 2007)). 

The parties touch upon two aspects of our holding in Dunkle. The first being the 

conclusion that testimony concerning the reasons why child victims of sexual assault 

delay reporting sexual assaults, omit reporting details of sexual assaults, or are unable to 

recall details of sexual assaults was easily understood by laypersons and did not require 

expert analysis. With respect to this holding, Appellant agrees that Section 5920 is a 

proper exercise of legislative authority insofar as it deems admissible certain expert 

testimony involving facts and opinions regarding specific types of victim responses and 
[J-17-2020] - 22

victim behaviors to sexual abuse. The Commonwealth similarly does not take issue with 

the legislature’s authority to statutorily allow such testimony, but maintains the provision

merely creates a means for admission of expert testimony on this topic when appropriate

and does not necessarily preclude lay witnesses from also commenting on this topic.

We agree with Appellant that Section 5920 effectively overruled Dunkle in this 

regard. In Olivo, this Court found that Section 5920 did not violate our exclusive control 

over judicial procedures pursuant to Article V, Section 10(c) of the Pennsylvania 

Constitution. Olivo, 127 A.3d at 770. We concluded that the statute constituted a rule of 

evidence governable by statute, and also deemed it “substantive rather than procedural 

as it permits both parties to present experts to testify to facts and opinions regarding 

specific types of victim responses and victim behaviors.” Id. at 780 (citing Commonwealth 

v. Newman, 633 A.3d 1069, 1071 (Pa. 1993) (“Subject only to constitutional limitations, 

the legislature is always free to change the rules governing competency of witnesses and 

admissibility of evidence.”)). Olivo did not provide us with an opportunity to comment on 

the continued validity of Dunkle in light of the provision. However, based on Olivo, which 

found Section 5920 to be a proper exercise of legislative authority, as well as our above 

analysis recognizing that such testimony falls within the realm of expert testimony under 

our rules of evidence and Huggins, we now necessarily hold that Section 5920 effectively 

overruled Dunkle to the extent that case can be read as categorically prohibiting expert 

testimony concerning victim behavior in response to sexual abuse due to it being within 

the ken of laypeople and not requiring expert analysis. See Olivo, 127 A.3d at 781 

(Saylor, C.J., concurring) (opining legislature’s intent in enacting Section 5920 was to 

remove appearance of per se prohibition erected by some of the language used in 

Dunkle). We disagree with the Commonwealth’s assertion that Section 5920 does not 

preclude lay opinion testimony on this topic, but merely created an avenue for expert 
[J-17-2020] - 23

testimony when appropriate. To conclude that some lay testimony on this subject matter

is permissible would undermine our conclusion that the behavior of child sexual assault 

victims is beyond that generally understood by the average layperson.

Both parties, to some degree, also touch on the other aspect of our holding in 

Dunkle, which found that expert testimony on this topic invades the jury’s province of 

determining witness credibility. They seem to agree that any interpretation of Section 

5920 must comport with this prohibition. Appellant, however, reads broadly our holding 

in Dunkle, asserting that all testimony in this regard violates this mandate. Such an 

interpretation would of course prohibit the Commonwealth entirely from introducing 

testimony like that provided by Detective Holzwarth in this case. To the contrary, the

Commonwealth does not believe such testimony categorically violates this proscription. 

We are in substantial agreement with the Commonwealth on this point. 

It is well-settled that expert testimony on the issue of a witness’s credibility is 

impermissible, as it encroaches on the province of the jury to make such determinations. 

See e.g., Maconeghy, 171 A.3d at 712 (holding inadmissible expert testimony that a 

particular complainant was a victim of sexual abuse as it invaded the province of the jury 

relative to determining credibility); Commonwealth v. Davis, 541 A.2d 315 (Pa. 1988) 

(holding trial counsel ineffective for failing to object to expert testimony that children 

typically have had some sort of sexual experience in order to report abuse because such 

testimony assessed children’s truthfulness); Seese, 517 A.2d at 921 (holding 

impermissible expert testimony that young children lack the sexual knowledge to supply 

details about sexual encounters and therefore usually do not fabricate stories of sexual

abuse because such testimony encroached on jury’s province to determine credibility); 

Commonwealth v. O’Searo, 352 A.2d 30, 32 (Pa. 1976) (holding that issue of witness 

credibility is within the knowledge of the average layperson and must be determined 
[J-17-2020] - 24

solely by the factfinder). Notwithstanding, we decline to read Dunkle so broadly as to 

preclude all expert testimony concerning victim responses and behaviors to sexual 

assaults. While some testimony on this topic may be prohibited for impermissibly 

invading the jury’s province of determining credibility, we disagree that all testimony will. 

Whether or not this prohibition has been violated must instead be assessed on a case by 

case basis. 

We additionally note that Section 5920 complies with this notion on its face, as it 

explicitly provides that a properly qualified expert may testify to facts and opinions 

regarding specific types of victim responses and behaviors in certain criminal proceedings 

involving sexual assaults, provided experts do not offer opinions regarding the credibility 

of any witness, including the victim. See 42 Pa.C.S. § 5920(b)(3) (“The witness’s opinion 

regarding the credibility of any other witness, including the victim, shall not be 

admissible.”). For these reasons, we hold that Dunkle remains valid insofar as it 

precludes expert testimony concerning victim responses and behaviors that touch upon

witness credibility, but decline to find that the case categorically precludes expert 

testimony concerning victim behavior in response to sexual abuse. This said, whether 

Detective Holzwarth’s testimony complies with the foregoing admissibility considerations

is a question for the trial court upon remand. 

V. Conclusion

Accordingly, we reverse the judgment of the Superior Court and remand this matter

for a new trial consistent with this opinion.

Chief Justice Saylor and Justices Baer, Todd, Donohue, Dougherty and Wecht join the 

opinion.