OPINION
STEWART, Judge.A jury convicted William L. Wurthmann on nine counts of sexual abuse of a minor-five counts of first-degree,1 two counts of second-degree,2 and two counts of third-degree3 -for sexually abusing his live-in girlfriend's daughter. Wurthmann appeals his conviction, arguing that the superior court erred in denying his motion for judgment of acquittal on the two counts of third-degree sexual abuse of a minor. Wurthmann also argues that the superior court committed reversible error by not instructing the jury that it must reach unanimity on specific incidents of sexual abuse. Finally, Wurthmann argues that the court abused its discretion by failing to redact a police detective's opinions on Wurthmann's credibility contained in a videotaped interview that was played to the jury. We conclude that Wurthmann's claims are without merit and affirm the decision of the superior court.
Facts and proceedings
Wurthmana moved in with ML., AL's mother, in 1987, when AL. was ten years old. Although Wurthmann never formally married M.L., he assumed the role of A.L .s stepfather. Wurthmann was generally unemployed and was A.L.'s primary caretaker. In addition to spending time with A.L., and taking her shopping and to the movies, Wurthmann was the disciplinarian.
AL. testified that Wurthmann began giving her backrubs when she was ten or eleven years old. He then began touching her breasts. When she was twelve years old, Wurthmann penetrated AL's vagina with his finger. This sexual touching progressed to an "everyday routine" of fellatio, eunnilin-gus and sexual intercourse that began when AL. was twelve years old and continued until she left for college. AL. was able to de-seribe numerous specific incidents of sexual abuse by Wurthmann, including instances in which he rubbed and digitally penetrated her vagina while she lay in bed; performed eun-nilingus in the living room; and engaged in sexual intercourse in front of the fireplace, outdoors in the shed, in Wurthmann's and M.L.'s bed, in A.L 's bed, and in a car in a parking lot.
Wurthmann admitted in an interview with police that he had a consensual sexual relationship with AL. after she turned seventeen, but denied the allegations of earlier abuse. At trial, Wurthmann did not testify or present evidence. His strategy was to attack A.L 's credibility regarding the earlier incidents of sexual abuse by impeaching her with her prior inconsistent statements to the police. He argued that AL. made up the childhood sexual abuse so she would not have to admit to her mother that she had stolen her mother's boyfriend.
Wurthmann also moved for judgment of acquittal on two counts of third-degree sexual abuse of a minor, arguing that he could not be convicted for having sex with A.L. when she was sixteen and seventeen years old because he did not occupy a "position of authority" over her.4 Superior Court Judge *764Eric T. Sanders concluded that whether Wurthmann was in a position of authority over A.L. for purposes of third-degree sexual abuse was a question of fact, and permitted Wurthmann to argue to the jury that he did not occupy that position with respect to A.L.
The jury convicted Wurthmann on all nine counts. Judge Sanders sentenced Wurth-mann to a composite sentence of 15 years with 3 years suspended.
Did the superior court err in denying Wurthmanm's motion for judgment of acquittal on the two counts of third-degree sexual abuse?
Wurthmann argues that the superior court erred by not granting his motion for judgment of acquittal on counts eight and nine, which charged him with third-degree sexual abuse for having sexual intercourse with A.L. in the car on the way back from a rafting trip when she was sixteen years old, and at home when she was seventeen.
Under AS 1141.488(a)(2), a person is guilty of third-degree sexual abuse of a minor if "being 18 years of age or older, the offender engages in sexual penetration with a person who is 16 or 17 years of age and at least three years younger than the offender, and the offender occupies a position of authority in relation to the victim." Wurth-mann argues that this court should reverse his conviction on these counts because he did not occupy a "position of authority" over A.L. Wurthmann concedes that he lived with A.L. and exercised authority over her as a father figure. But he argues that the legislature intended "position of authority" for purposes of the third-degree sexual abuse statute to "mean something more than merely acting like a father." 5
The prohibition against sexual contact with sixteen- and seventeen-year-olds by persons in "positions of authority" was added to the sexual abuse statutes in 1990. - These changes were precipitated by the Satch Carlson case.6 Carlson, an Anchorage high school teacher, had been charged with two counts of sexual abuse of a minor in the first degree7 and one count of sexual abuse of a minor in the second degree8 after he had sex with a seventeen-year-old student.9 The statutes in effect at that time prohibited adults from having sex with sixteen- and seventeen-year-old minors entrusted to their care "by authority of law."10 Superior Court Judge Karl S8. Johnstone determined that this language prohibited sex with children in this age bracket by legal guardians, but not by teachers.11
In response to the Caurison decision, the legislature amended the sexual abuse statutes to prohibit sexual contact with sixteen- and seventeen-year-olds by adults in "positions of authority."12 The legislature intended this prohibition to encompass not just teachers, but "substantially similar" adults "in positions that enable them to exercise undue influence over children."13 Alaska Statute 11.41.470 was amended in 1990 to provide a non-exclusive list of the individuals who occupy positions of authority under this definition:
(5) "position of authority" means an employer, youth leader, scout leader, coach, teacher, counselor, school administrator, religious leader, doctor, nurse, psychologist, guardian ad litem, babysitter, or a substantially similar position, and a police officer or proba*765tion officer other than when the officer is exercising custodial control over a minor.14
Contemporaneously with these amendments to the third-degree sexual abuse statute, the phrase "position of authority" was deleted from AS 1141. the subsection of the first-degree sexual abuse statute that prohibited an adult who had no legal or biological relationship with a child under sixteen years of age from having sex with that child when the victim is "residing as a member of the social unit in the same household as the offender and the offender is in a position of authority over the victim." 15 The subsection was amended to read: "the victim at the time of the offense is residing in the same household as the offender and the offender has authority over the victim."16 Subsection (a)(B)(B) was amended at the same time to prohibit sex with a child under sixteen by an adult who "occupies a position of authority in relation to the victim," regardless of whether that adult is living in the same household as the child."17
Because of this distinction, Wurthmann contends that "position of authority" for purposes of the sexual abuse statutes must mean something more than "merely acting like a father" or the "has authority" language in AS 1141434(a)(8)(A) would be completely subsumed within subsection (a)(8)(B) and would be surplusage.
We agree with Wurthmann that this change in the wording in the first-degree sexual abuse statute has only one reasonable explanation: the legislature intended to distinguish between an individual who lives in the same household and "has authority" over a child and one who occupies a "position of authority" over a child as defined in AS 11.41.470(5). But we disagree that a person who "has authority" over a child under AS 11.41484(a)(8)(A) can in no circumstances also occupy a "position of authority" over that child. Wurthmann offers no evidence from the legislative history of the 1990 amendments to the sexual abuse statutes to indicate that the legislature intended this result.
[1] A more persuasive explanation is that the legislature reworded AS 11.41.484(a)(8)(A) to delete "position of authority" because it did not want to require proof of this additional element, as newly defined in AS 1141.470(5), to find that a household member had committed first-degree sexual assault. A roommate, adult step-sibling, or live-in boyfriend might, depending on the dynamics of the household, the personalities of the individuals involved, and the amount of authority the legal or biological parent delegates, have only limited and intermittent authority over a child in the household. But a live-in boyfriend who assumes the position of a stepfather has additional influence by virtue of his status as a person of special trust in the child's life.18 Although the first-degree sexual abuse statute prohibits sexual abuse of children under sixteen by both categories of offenders, the third-degree statute, which punishes sexual conduct with older children, reaches only offenders who by virtue of their position in relation to the child-irrespective of the level of authority they actually exercise-have undue influence over a child.19 Judge Sanders correctly con*766cluded that this is a fact-bound inquiry appropriately left to the jury.20
[2] Generally, criminal - statutes - are strictly construed in favor of the defendant.21 But "[s)trict construction does not require that statutes be given the narrowest meaning allowed by the language; rather, the language should be given 'a reasonable or common sense construction, consonant with the objectives of the legislature.'"22 The 1990 revisions were expressly intended to extend the reach of the sex abuse statutes to persons "in positions that enable them to exercise undue influence over children."23 As the State points out, it would be unreasonable to attribute to the legislature an intent to impose criminal liability on a babysitter or teacher but not a live-in boyfriend who assumes the role of a stepfather and is even better positioned to manipulate a child in his care.24
[3] Wurthmann's argument that live-in boyfriends necessarily fall outside the reach of AS 11.41.438(2) is not supported by the language and history of the sexual abuse statutes and is contrary to the legislature's intent to criminalize sexual conduct with sixteen- and seventeen-year-old minors by adults in positions of authority. Because Wurthmann assumed authority over A.L. not just as her mother's live-in boyfriend, but as AL's stepfather and primary caretaker, a reasonable jury could conclude that he exercised undue influence over A.L. and was in a "position of authority" over her for purposes of AS 1141438(a)(2).25 We thus reject Wurthmann's claim that the superior court erred in denying his motion for judgment of acquittal.
Does the superior court's erroncous Covington instruction require reversal?
During the discussion of jury instructions, the parties and the court discussed the need for an instruction under Covington v. State26 that the jury must agree unanimously that the defendant committed the specific incident of sexual abuse charged in each count of the indictment. The parties and the court agreed on an instruction to meet this requirement. However, the instruction that the court actually gave was not the agreed instruction. Instead, Judge Sanders instructed the jury that it only needed to unanimously agree that the particular type of sexual conduct alleged in each count-for example, digital penetration-had occurred in the relevant period. That instruction permitted the jury to convict the defendant without agreement on a specific incident of abuse for each count.
[4, 51 The parties agree that this instruction did not meet the Covington requirements that the jury must unanimously agree that a specific incident of sexual abuse alleged in a count of the indictment occurred within the time period covered by the count. However, Wurthmann failed to object when this instruction was read to the jury.27 But because an erroneous Covington instruction implicates a defendant's constitutional right to a unanimous verdict, we review his claim *767for plain error."28 An error affecting constitutional rights is harmless under a plain error analysis if it did not appreciably affect the verdict.29
In Covington I, and on rehearing in Cov-ington II, we concluded that Covington was denied his right to a unanimous verdict because the State did not elect a specific incident of sexual abuse within each count to support Covington's conviction and because no clarifying instruction was given requiring the jury to unanimously agree on specific incidents of sexual abuse.30 We described the cireumstances under which such an error would be prejudicial and require reversal:
In a case where discrete incidents of sexual abuse are charged together in a single count, and impeaching and contrary evidence of differing weight is offered to rebut the several incidents, a real possibility exists that individual jurors will reject some incidents, based upon an evaluation of the impeaching and contrary evidence, but accept other incidents as proven. In such a case, the twelve jurors may agree that the defendant committed at least one of the incidents, but be in general disagreement as to which incident that was.31
We concluded that these cireumstances were not present in Covington. The complaining witness had shared a bed with her father for years and had engaged in sexual intercourse almost every night.32 She thus was not able to differentiate between various incidents of sexual abuse.33 Covington denied that he had ever had sex with his daughter. Under these civeumstances, "no impeaching or contrary evidence was more applicable to one incident than another" and the jury was faced with a straight question of credibility.34 The jury's verdict convicting Covington on all counts established that it had accepted the daughter's testimony and rejected Covington's contrary claims."35
Wurthmann argues that the superior court's erroneous Covington instruction was not harmless in his case because he impeached A.L. about specific incidents of sexual abuse. Because the only specific incidents Wurthmann impeached were AL's allegations that he had digitally penetrated her at age twelve and engaged in sexual intercourse with her at age thirteen, he is in effect arguing that the jury may have convicted him on counts I and III, two counts of first-degree sexual assault, without reaching unanimity on an underlying incident of abuse.
This argument fails as to count I because AL. described only one specific incident of digital penetration that occurred when she was twelve, the age covered by this count. Wurthmann attempted to impeach A.L. with her prior statement to police that the first incident of digital penetration occurred when she was thirteen. The jury, by convicting Wurthmann on this count, must have rejected his impeaching evidence and unanimously agreed that the incident A.L. related at trial had been proved beyond a reasonable doubt.
Wurthmann's argument also fails as to count III because Wurthmann challenged only one of two separate incidents of sexual intercourse alleged during the time period covered by this count. Even assuming that the jury rejected AL trial testimony regarding the first incident of sexual intercourse in front of the fireplace because it was inconsistent with her initial statement to police, it is unlikely that the jury would have rejected AL's uncontradicted testimony regarding a second incident that occurred in the shed. The fact that the jury convicted Wurthmann on all counts indicates that it accepted AL's testimony that Wurthmann *768began abusing her when she was twelve years old and rejected Wurthmann's claim that A.L. had fabricated the abuse. (Ctiven the jury's credibility determination, there is little doubt that the jury would have reached unanimity on the second incident of sexual abuse that Wurthmann failed to impeach or contradict.
[6] We conclude that the trial court's error in failing to instruct the jury on the need for unanimity as to specific incidents of sexual abuse was harmless. Given the evidence and the jury's credibility determination, it cannot be fairly said that the jury would have failed to reach unanimity on the conduct alleged if it had been properly instructed.36
Did the superior court abuse its discretion by not redacting the detective's opinions from an interview played to the jury?
[7] Wurthmann next argues that Judge Sanders erred in declining to redact statements Detective Randy Carroll made in a pre-arrest interview of Wurthmann that indicated that he believed A.L.'s allegations of sexual abuse and disbelieved Wurthmann's denials. The videotape of this interview was played to the jury.
In his interview of Wurthmann, Detective Carroll said he believed that A.L.'s allegation that the sexual abuse had spanned years was closer to the truth than Wurthmann's claim that a sexual relationship did not begin until AL. was seventeen years old. Wurthmann argued at trial that admitting Carroll's assertions regarding Wurthmann's credibility would be reversible error. Judge Sanders disagreed and declined to redact these statements of opinion. However, Judge Sanders noted that he would provide the jury a limiting instruction that Carroll's comments were not admitted for the truth but to give context to Wurthmann's answers.
Detective Carroll stated in this interview that he believed Wurthmann had sexual contact with A.L. when she was under seventeen because of admissions Wurthmann had made in his letters to A.L. Because these letters were admitted into evidence, the jury had the opportunity to independently evaluate the basis for Carroll's suspicions. Moreover, Carroll's comments were so integral to the interview that their removal would have deprived the jury of the context for Wurth-mann's statements.37 Furthermore, Carroll testified that his statements were part of an interview strategy designed to encourage Wurthmann to admit his criminal conduct. Thus, there was little risk of prejudice from Carroll's comments.38 We conclude that Judge Sanders did not abuse his discretion by declining to redact Carroll's statements.39
Conclusion
The judgment of the superior court is AFFIRMED.
. AS 11.41.434(a)(1), (a)(3)(8).
. AS 11.41.436(a)(2).
. AS 11.41.438(a)(2).
. See AS 11.41.438(a)(2).
. We apply our independent judgment in interpreting statutes. See Conner v. State, 696 P.2d 680, 682 (Alaska App.1985).
. See Committee Minutes, House Health, Education and Social Services Standing Committee hearing on S.B. 355 (March 9, 1990).
. Former AS 11.41.434(a)(2)(A).
. - Former AS 11.41.436(a)(3)(A).
. See State v. Carlson, No. 3AN-S89-7443 CR (Alaska Super., January 18, 1990).
. Former AS 11.41.434(a)(2)(A); former AS 11.41.436(a)(3)(A).
. See Carlson, No. 3AN-S89-7443 CR at 4.
. See AS 11.41.438(a)(2); ch. 151, § 3, SLA 1990.
. Letter of Intent for S.B. 355, 1990 House Journal 4199; 1990 Senate Journal 4220.
. Ch. 151, § 5, SLA 1990.
. Emphasis added. The following changes were made to AS 11.41.434(a)(3)(A)-(B):
(a) An offender commits the crime of sexual abuse of a minor in the first degree if
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(3) being 18 years or older, the offender engages in sexual penetration with a person who is under 16 years of age, and
(A) the victim at the time of the offense is [ (A)] residing [AS A MEMBER OF THE SOCIAL UNIT] in the same household as the offender and the offender has [IS IN A POSITION OF] authority over the victim; or
(B) the offender occupies a in relation to the victim [TEMPORARILY ENTRUSTED TO THE OFFENDER'S CARE].
See ch. 151, § 1, SLA 1990.
. AS 11.41.434(a)(3)(A); see supra (emphasis added) note 14.
. Emphasis added. See supra note 14.
. Cf. Carterv. Brodrick, 644 P.2d 850, 855 (Alaska 1982) (holding that a stepchild is a "child of the marriage" for purposes of granting visitation to a stepparent if the stepparent has assumed the status of in loco parentis).
. See AS 11.41.470(5); Leiter of Intent for S.B. 355, 1990 House Journal 4199; 1990 Senate Journal 4220.
. See State v. Beason, 2 P.3d 459, 463 (Utah App.2000) (quoting Uiah Code Ann. § 76-5-404.1(3)(h) (1995) ("Whether a person not specifically listed in the statute was in a position of special trust, defined as a 'position of authority, who, by reason of that position is able to exercise undue influence over the victim,' ... presents a question of fact to be determined by the trier of fact in each case.")).
. See Conner, 696 P.2d at 682.
. Id. at 682 (quoting Belarde v. Anchorage, 634 P.2d 567, 568 (Alaska App.1981)); see also Hill-man v. Anchorage, 941 P.2d 211, 215 (Alaska App.1997) (courts should avoid construing statutes to defeat the obvious legislative purpose).
. Letter of Intent for S.B. 355, 1990 House Journal 4199; 1990 Senate Journal 4220; Committee Minutes, Senate Judiciary Committee Hearing on $.B. 355 (January 23, 1990).
. See Peters v. State, 943 P.2d 418, 420 (Alaska App.1997) (statutes dealing with the same or related subject matier should be construed as harmoniously as possible).
. See Willett v. State, 836 P.2d 955, 957 (Alaska App.1992).
. 703 P.2d 436 (Alaska App.1985) (Covington I), modified on reh'g, 711 P.2d 1183 (Alaska App. 1985) (Covington IT).
. See Alaska R.Crim.P. 30.
. See Covington II, 711 P.2d at 1184 (citing Alaska R.Crim. P. 47(b)). Alaska R.Crim.P. 47(b) provides: "Plain errors or defects affecting substantial rights may be noticed although they were not brought to the attention of the court."
. See Covington II, 711 P.2d at 1185 (citing Van Haiten v. State, 666 P.2d 1047, 1056-57 (Alaska App.1983)).
. - See id. at 1184 (citing Covington I, 703 P.2d at 441).
. Id. at 1185.
. See id.
. See id.
. Id.
.
. See Covington II, 711 P.2d at 1185; Love v. State, 457 P.2d 622, 630-32 (Alaska 1969).
. See Linne v. State, 674 P.2d 1345, 1356 n. 8 (Alaska App.1983) (court did not err in failing to exclude hearsay portions of videotaped interview with defendant because the jury could not have understood defendant's responses without hearing the questions that elicited them).
. See Sakeagak v. State, 952 P.2d 278, 282-83 (Alaska App.1998).
. See Hawley v. State, 614 P.2d 1349, 1361 (Alaska 1980) (trial court's evidentiary rulings reviewed for abuse of discretion).