United States v. Wilson

Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 1 FILED United States Court of Appeals PUBLISH Tenth Circuit UNITED STATES COURT OF APPEALS September 9, 2026 Christopher M. Wolpert FOR THE TENTH CIRCUIT Clerk of Court _________________________________ UNITED STATES OF AMERICA, Plaintiff - Appellee, v. No. 24-7093 MASON ANTHONY WILSON, Defendant - Appellant. _________________________________ Appeal from the United States District Court for the Eastern District of Oklahoma (D.C. No. 6:23-CR-00062-KWR-1) _________________________________ Jonathan D. Reppucci, Reppucci Law Firm, P.C., Denver, Colorado, for Defendant - Appellant Mason Anthony Wilson. Linda A. Epperley, Assistant United States Attorney (Christopher J. Wilson, United States Attorney with her on the brief), Muskogee, Oklahoma, for Plaintiff - Appellee United States of America. _________________________________ Before MATHESON, EBEL, and CARSON, Circuit Judges. _________________________________ EBEL, Circuit Judge. _________________________________ When his two-month-old daughter was discovered to have a litany of severe, unexplained injuries only days after he became her sole, primary caregiver, Defendant Mason Anthony Wilson was charged with child abuse and child neglect.  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 2 After a two-day trial, which included testimony from a child abuse and neglect specialist, multiple law enforcement officials, and his wife, Wilson was convicted on both charges. He now challenges those convictions, raising several arguments, many of which are raised for the first time on appeal. Because some of his arguments were waived, and those that were not either lack merit or had no impact on the outcome of his trial, we AFFIRM. I. BACKGROUND A. Charged conduct In February 2022, Appellant Mason Wilson had a baby, B.W., with Bailey Henson, who also had another child of her own. Henson was an employee at a credit union, but for two months after B.W.’s birth, Henson stayed home to care for B.W. along with Wilson. No issues arose in these two months. Then, on April 11, Henson returned to work, leaving Wilson to care for B.W. during the day. Within the next three days, Henson noticed a bruise on B.W.’s cheek and a scratch on B.W.’s arm. She decided not to take B.W. to the hospital immediately because they already had a scheduled check-up on April 14. She asked Wilson about the cheek bruise, to which he initially responded that he was holding B.W. and B.W. “slung her head back and had hit her face on” Wilson’s chest and collarbone, and potentially his necklace. (Record on Appeal (“ROA”) v.3 65.) On April 14, Wilson took B.W. to the pediatrician’s checkup along with his father-in-law. The pediatrician said they needed to go to the hospital. Ms. Henson met them at the 2  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 3 pediatrician’s office and they drove to the hospital together. The pediatrician alerted the Oklahoma Department of Human Services (“DHS”). Further examination revealed other extensive injuries. B.W. had ten broken bones, including five broken ribs, a proximal ulnar fracture in her left arm, and corner metaphyseal fractures on her right tibia, left tibia, and left femur. B.W. had injuries on both ears. B.W. had bruising on her face, arms, fingers, neck, buttocks, wrist, back, and stomach. B.W. had scratches on her body, including a scar on her forearm and a mark above her vagina. Henson again asked Wilson how these injuries occurred, and this time Wilson said that B.W. had fallen off the bed. Later, Wilson said he lightly “stepped on her.” Dist. Ct. Mem. Op. & Order (July 31, 2024) at 2. He also asked Henson to say she rolled over onto B.W. to “take heat off” him. (ROA v.5 156.) Both Wilson and Henson were interviewed by Dr. Christine Beeson, a specialist in child abuse and neglect. Henson told Dr. Beeson that B.W. had hit her face on Wilson’s collarbone and fallen off the bed, based on what Wilson had told her. Separately, Wilson told Dr. Beeson that B.W. had fallen off the bed. Dr. Beeson concluded that B.W.’s injuries were not consistent with the explanations provided. Rather, the several distinct bone breaks suggested multiple direct blows and forceful pulls or yanks in the previous five days. The bruising on each ear suggested multiple forceful hits because of the difficulty of bruising ears and the different planes of the injuries. The cheek bruise and abdominal bruise suggested forceful events because babies’ cheeks and stomachs do not bruise easily. A linear 3  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 4 bruise on B.W.’s wrist suggested “a direct blow or a squeeze-type injury.” (ROA v.3 181.) The scratches suggested someone other than B.W. scratched her because two- month-olds cannot scratch their own neck. A subconjunctival hemorrhage below B.W.’s left eye also suggested a direct blow. Wilson was also interviewed by James Poffel, a sergeant with the local police department, Abram Springer, a child welfare specialist at DHS, and Ashley Chavez, an FBI special agent. Wilson continued to state that the cheek bruise was the result of B.W. hitting her face on his collarbone, though he could not explain the other injuries. B. Trial. Wilson was indicted via federal grand jury in the Eastern District of Oklahoma on one count of Child Abuse in Indian country and one count of Child Neglect in Indian country, in violation of 21 Okla. Stat. § 843.5(A) & (C) and 18 U.S.C. §§ 1151 and 1153, based on Wilson’s membership in the Cherokee Nation. During the two-day trial, the prosecution called several witnesses, including Dr. Beeson, Henson, Poffel, and Springer. Dr. Beeson was brought as an expert witness, while the other three were brought as lay witnesses. The defense called one witness, Wilson’s great-uncle, who testified as to Wilson’s character. Prior to trial, the prosecution disclosed Dr. Beeson’s testimony as follows: 1. Dr. Beeson will testify to all aspects of her knowledge, training, and experience in the area of child physical abuse and neglect and child abuse and neglect examinations, in particular: a. Her education, background, training, and experience; 4  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 5 b. Her knowledge and experience in the area of child physical abuse and neglect; c. Her knowledge of all aspects of human anatomy, the mechanism of injuries in child physical abuse, and the injuries sustained as a result of child physical abuse; and d. Her knowledge regarding the importance of history, her experience in obtaining history from parents and/or potential perpetrators, and all factors used to determine between accidental or non-abusive trauma and abusive trauma. 2. Dr. Beeson will testify regarding her involvement in this case, in particular: a. Her observation and examination of the victim in this case; b. Her review of the records, reports, photographs, medical records, medical history, etc., regarding the victim; c. Her knowledge regarding the victim’s injuries, including expected levels of pain sustained by the victim; and d. Her medical diagnosis of child physical abuse 3. The bases for Dr. Beeson’s opinion include: a. Her education, training, experience, and knowledge; b. Her observation and examination of the victim in this case; c. John M. Leventhal et al., Fractures in young children: distinguishing child abuse from unintentional injuries, 147 Am. J. Diseases of Children 87 (1993); d. Naomi F. Sugar et al., Bruises in infants and toddlers: those who don’t cruise rarely bruise, 153 Arch. Ped. Adolesc. Med. 399 (1999); e. David L. Chadwick et al., Annual risk of death resulting from short falls among young children: less than 1 in 1 million, 121 Pediatrics 1213 (2008). ROA v.1 21‒22 (Gov’t’s Notice of Intent to Offer Expert Test.). Wilson sought a Daubert 1 hearing to discuss Dr. Beeson’s testimony as to the pain B.W. experienced. The district court ultimately limited Dr. Beeson’s testimony on B.W.’s pain. Wilson raised two other objections to Dr. Beeson’s testimony at trial: 1) that her medical diagnoses of child abuse and neglect were invading the province of the jury to reach a legal conclusion as to child abuse and neglect, and 2) that her statements relating to 1 Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993). 5  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 6 what she would expect a parent to do based on B.W.’s injuries were invading the province of the jury, apparently because jurors are aware of parental expectations in the event of injuries and it was suggestive of Wilson’s mens rea. Henson testified to seeing the cheek bruise after returning to work and that Wilson had told her “different things” about the origin of the bruise. (ROA v.5 134.) Henson conveyed the different stories that Wilson had told her regarding the injuries. Henson said that at some point during her interactions with Wilson, “I asked him not to lie to me again.” (ROA v.3 86.) Springer testified that during his interview with Wilson, Wilson attributed the facial bruises to B.W. hitting her face on his collarbone. Springer said it was common for child abusers to minimize the victim’s injuries. Defense counsel objected when the prosecution asked for an example, and the district court sustained the objection as approaching expert testimony. Springer then testified, without objection, that it was common for child abusers to proffer accidental causes, including falling off the bed. Poffel testified to his interviews with Wilson and Henson and his review of the records in the case. Poffel testified that in his experience, ear bruises are “almost always indicative of child abuse.” (Id. at 241.) Poffel also testified that, when interviewing a potential perpetrator, it is an indicator of dishonesty if their explanations are not consistent with the injuries, and that perpetrators often minimize the abuse. Defense counsel objected that this was approaching expert testimony, but the court overruled the objection. Poffel also stated that perpetrators often offer 6  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 7 accidental causes of injuries. Finally, he said it is an indicator of dishonesty if someone gives different explanations to different people. In closing, the prosecution stated that “All the United States needs to prove is that when the defendant drew his hand back to hit B.W., or when he yanked on her legs, or squeezed her chest, or pinched her ears, his actions were not an accident.” (Id. at 297.) The prosecution referred to Wilson’s innocent explanations of the injuries as “a stupid story.” (Id. at 312.) Finally, the prosecution said Wilson “needs to be held accountable for his actions” and “whether or not B.W. gets justice [is] in your hands.” (Id. at 305, 317.) The jury entered a guilty verdict on both charges. Wilson moved for a new trial, saying the verdict was contrary to the weight of the evidence and the prosecution had violated Federal Rule of Criminal Procedure 16(a)(1)(G) by insufficiently disclosing in its expert witness disclosure that Dr. Beeson would testify as to the modality of B.W.’s injuries, not just that the injuries were non-accidental. The district court denied Wilson’s motion and sentenced him to 120 months in prison. II. STANDARD OF REVIEW We review evidentiary issues that were objected to below for abuse of discretion. United States v. Bycroft, 174 F.4th 814, 817 (10th Cir. 2026), petition for cert. filed (U.S. Aug. 6, 2026) (No. 26-5242). “A district court abuses its discretion in admitting evidence if that admission represents ‘a clear error of judgment or exceed[s] the bounds of permissible choice in the circumstances.’” Id. (alteration in original) (quoting Gilbert v. 7  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 8 Cosco, Inc., 989 F.2d 399, 402 (10th Cir. 1993)). Conversely, issues that were not objected to below are reviewed for plain error. United States v. Poterbin, 162 F.4th 1254, 1266 (10th Cir. 2025). To establish plain error, there must be 1) an error, 2) that is plain, 3) that affects the defendant’s substantial rights, and 4) that “substantially affects the fairness, integrity, or public reputation of judicial proceedings.” Id. (internal quotation marks omitted). Yet, if the appellant “fails to make a plain-error argument on appeal, we ordinarily deem the issue waived . . . and decline to review the issue at all— for plain error or otherwise.” United States v. Dermen, 143 F.4th 1148, 1205 (10th Cir. 2025) (quoting United States v. Leffler, 942 F.3d 1192, 1196 (10th Cir. 2019)), cert. denied, 146 S. Ct. 1622 (2026). Because some of Wilson’s arguments on appeal were preserved and others were not, we will address each with the accompanying discussion below. III. DISCUSSION Wilson raises three main grounds for reversing his conviction. First, he argues that multiple aspects of Dr. Beeson’s expert testimony were impermissible. Second, Wilson argues that the lay witnesses testified improperly. Third, Wilson raises several statements from his trial that he claims constituted prosecutorial misconduct. If none of the arguments raised individually warrant reversal, he also asserts that we should vacate 8  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 9 his conviction on cumulative error. None of Wilson’s arguments, including cumulative error, merit reversal. A. Dr. Beeson’s Testimony Wilson takes issue with three aspects of Dr. Beeson’s testimony. We will address each in turn. a. Diagnoses of child abuse and neglect Wilson argues that the district court abused its discretion by permitting Dr. Beeson to testify that she had diagnosed B.W. with child abuse and child neglect. It appears that Wilson’s main concern is that the medical terms “child abuse” and “child neglect” mirror the legal terms used in his charges. At trial, when Dr. Beeson was asked about her diagnoses, Wilson’s counsel objected that “we’re definitely getting into the province of the jury.” (ROA v.3 203.) By stating that she had diagnosed B.W. with child abuse and neglect, the argument goes, Dr. Beeson was telling the jury what verdict to reach. Because Wilson preserved his objection below, we review for abuse of discretion. We conclude that the district court did not abuse its discretion by permitting Dr. Beeson’s testimony. Dr. Beeson’s diagnoses were permissible. First, Dr. Beeson did not conclude that Wilson had committed child abuse or neglect; rather, she diagnosed B.W. with child abuse and neglect. That would leave the question of who caused B.W.’s injuries to the jury. Second, Dr. Beeson’s medical diagnosis of child neglect required only a failure to “provide medical attention for bruising to a two-month-old.” (ROA v.3 202); see United States v. Keys, 638 F. Supp.3d 1282, 1291 (E.D. Okla. 2022) 9  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 10 (opinion testimony stating that “a failure to provide needed medical care, where . . . it is clear to any reasonable person that a child needs medical care” is diagnosable as “child medical neglect”). But a conviction for child abuse or neglect under 21 Okla. Stat. § 843.5 requires a finding of willfulness or malice. 21 Okla. Stat. § 843.5(A), (C). Nothing in Dr. Beeson’s testimony spoke to the perpetrator’s willfulness in abusing or neglecting B.W. It is possible to be abusive and neglectful negligently, recklessly, or knowingly. See Ibarra v. Holder, 736 F.3d 903, 911, 915 (10th Cir. 2013) (recognizing different mentes reae required for child abuse and neglect across states and civil and criminal contexts). So, the jury still had to make the additional inferences that Wilson caused B.W.’s injuries and that he acted willfully or maliciously. See United States v. Collins, No. 23-CR-144-JFH-1, 2023 WL 6842251, at *4 (E.D. Okla. Oct. 17, 2023) (unreported) (collecting cases). Additionally, courts are familiar with medical testimony that speaks in similar terms as legal distinctions but with different standards. For example, courts often permit testimony as to a defendant’s mental competency, sanity, and even motivation. See United States v. Austin, 981 F.2d 1163, 1164–65 (10th Cir. 1992) (permitting testimony of medical diagnosis of sanity); United States v. Dotson, 817 F.2d 1127, 1132 (5th Cir. 1987) (“[E]xpert’s summary merely explained his analysis of the facts indicating willful evasion, and did not . . . directly embrace the ultimate question of whether Dotson did in fact intend to evade income taxes.”), vacated in part on other grounds on rehearing, 821 F.2d 1034, 1035 (5th Cir. 1987) (per curiam); United States v. Cox, 826 F.2d 1518, 1520, 1524 (6th Cir. 1987) (permitting medical 10  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 11 testimony of defendant’s mental illness and its effect on him at the time of the offense). Since Dr. Beeson’s testimony did not stipulate an element of the crime— i.e., willfulness—this testimony was permissible. Cf. Fed. R. Evid. 704(b). And the prosecution made clear to the jury that “a medical diagnosis [is] not a factual legal conclusion as the jury will be asked to make.” (ROA v.3 203.) It “only supplie[s] the factfinder with data from which it could draw the ultimate legal conclusion.” Cox, 826 F.2d at 1525. Dr. Beeson’s testimony was permissible, and thus the district court did not abuse its discretion by admitting it. Additionally, concerns with the terminology used at trial are best remedied by seeking clarification below, not seeking reversal on appeal. b. Parental expectations testimony Wilson next argues that it was improper for the district court to permit testimony regarding Dr. Beeson’s parental expectations—here, in the form of Dr. Beeson’s statements that she would expect a parent to seek medical attention based on the bruising to B.W.’s cheek. Wilson, on appeal, raises three distinct issues with the parental expectations testimony: 1) that it invaded the province of the jury, which he objected to at trial, 2) that it was not reliable nor relevant, which he did not object to at trial, and 3) that it was insufficiently disclosed in the prosecution’s Rule 16 notice, which he did not object to below. We review the first for abuse of discretion and the latter two for plain error. 11  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 12 i. The testimony did not invade the province of the jury First, Wilson argues that Dr. Beeson’s testimony invaded the province of the jury because parental expectations are “within the juror’s common knowledge and experience.” Aplt. Br. 18; United States v. Rodriguez-Felix, 450 F.3d 1117, 1123 (10th Cir. 2006). We disagree. During her testimony, Dr. Beeson had been discussing why a bruise on a baby’s cheek is particularly concerning, because a baby’s cheek is soft and fleshy without much bony structure underneath and therefore difficult to bruise, suggesting a great deal of force was necessary to cause the injury. The prosecution then asked: “But you’re a very highly trained, skilled pediatrician who is board certified in two areas. What if it’s just a parent who doesn’t have any fancy degrees? Do you expect that parent to provide medical attention for their baby in that condition?” (ROA v.3 201.) The context, then, suggests that the purpose of the question was to ascertain whether it is neglectful for such an injury to go unreported, even though the knowledge of why the injury was particularly troubling was enhanced by her specialized training and experience. We do not think it is clearly within the common knowledge and experience of a jury that a cheek injury for a baby is particularly troubling, nor what they would expect a parent to do if confronted with a cheek injury. The fact that such an injury is rare makes it less likely that the jury would have experience with this situation. So, Dr. Beeson’s testimony was useful for the jury to understand that the injury, 12  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 13 though perhaps more innocuous to a lay person than a child neglect specialist, should still prompt a parent to seek medical attention. Wilson also suggests that commenting on parental expectations was a “thinly veiled comment on Wilson’s mens rea.” Aplt Br. 19. For the same reason that Wilson’s argument relating to the medical diagnoses discussed above fails, this argument fails, too. Expert testimony is impermissible if the expert states “the final conclusion” that the jury must make at trial. United States v. Goodman, 633 F.3d 963, 970 (10th Cir. 2011) (internal quotation marks omitted). Here, that is “the very mental state at issue in the case—the defendant’s mens rea when he committed the crime.” Id. But an expert can discuss mental states at a more general level, not specific to the defendant. For example, prosecutors can ask “hypothetical questions mirroring the fact patterns of the trial case . . . when the answering testimony still allows the fact finder to make an additional inference as to whether the defendant had the mental state or condition constituting an element of the crime charged.” Id. In Goodman: The government did not ask the experts to give their opinions as to Goodman’s legal sanity. Rather, the prosecution posed hypothetical facts that mirrored the charged robberies and asked the experts whether the hypothetical robber’s actions were consistent with the behavior of someone with PTSD. The jury still needed to make an additional inferential step to determine whether or not Goodman was legally insane. Id. The same can be said here. Dr. Beeson stated what she would expect a parent to do in a hypothetical situation. Of course, that left the final question to the jury of whether Wilson himself was willfully neglectful in failing to seek medical care for 13  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 14 B.W. based on her injuries. Rather than preventing a witness from dictating what verdict a jury should reach, Wilson seemingly wishes to prevent witnesses from providing testimony that a jury could use to inform its verdict. ii. The testimony was relevant and reliable Second, Wilson argues that Dr. Beeson’s testimony was neither reliable nor relevant. Wilson argues that his objection at trial preserved his objection on these grounds, but we are not persuaded: his objection raised only the invasion of the province of the jury, which is a different argument. In fact, as to relevance, we find the suggestion that the testimony was irrelevant to be contradictory to the prior suggestion that the testimony usurped the role of the jury. Therefore, the failure to raise a separate objection would render this argument unpreserved, and we would review for plain error—and given his failure to brief plain error, it would be waived. That said, even on an abuse of discretion standard, Wilson’s arguments fail. The evidentiary test for relevance is that the testimony has “any tendency to make a fact. . . of consequence in determining the action” “more or less probable.” Fed. R. Evid. 401(a), (b). Seeing as Wilson has already argued the testimony invaded the province of the jury, we do not see how the testimony could also be irrelevant: if the testimony had no bearing on a fact of consequence, it could hardly be said to infringe on the jury’s role. In any event, given the relation to a diagnosis of medical neglect, we find the testimony was relevant. Wilson also argues that Dr. Beeson was not qualified to share her parental expectations because she is not a “psychologist, counselor, social worker, 14  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 15 parent/child investigator, parenting teacher, or any other type of parenting specialist.” Aplt. Br. 17. But Wilson continues to state that she has “extensive and impressive qualifications as a medical doctor and a child abuse and neglect pediatrics expert.” Id. Inherent to this specialty is knowledge of medical issues that have gone unreported that a reasonable person would know need medical attention. See Keys, 638 F. Supp. 3d at 1293 (finding “‘medical child neglect’ . . . where . . .it is clear to any reasonable person that a child needs medical care”); cf. United States v. Clark, 981 F.3d 1154, 1159 (10th Cir. 2020) (discussing child welfare specialist’s allegations of neglect based on failure to seek dental care for rotting teeth, failure to seek medical intervention for impacted bowel, failure to see optometrist for vision issues, and failure to seek medical attention for “history of defecating on himself”). To make a neglect diagnosis, a doctor would have to be knowledgeable as to what injuries should be brought to the attention of a doctor for treatment. Therefore, Dr. Beeson would seemingly be qualified to remark on whether she would expect a parent to seek medical attention for their baby’s injury. See Keys, 638 F. Supp. 3d at 1288 (permitting testimony that parent sought medical treatment and placed child in hospice care for illness that would not normally call for such care). Again, we conclude that Dr. Beeson’s testimony was permissible, so the district court did not abuse its discretion nor plainly err in admitting it. 15  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 16 iii. Wilson waived his argument that the prosecution’s Rule 16 disclosure was insufficient as to parental expectations Third, Wilson argues that Dr. Beeson’s testimony should have been excluded because it was not properly disclosed in the prosecution’s Rule 16 notice. Again, Wilson did not object below, and thus on appeal we would review for plain error. But Wilson’s briefs did not argue plain error, so this argument is waived. To be sure, Wilson did take issue with some aspects of the Rule 16 notice below. He sought a Daubert hearing on Dr. Beeson’s testimony relating to the pain B.W. would have experienced, and after the jury entered its verdict, he moved for a new trial based in part on the Rule 16 notice being insufficient because it failed to disclose that she would testify as to the specific modality of B.W.’s injuries—i.e., that the injuries were likely caused by direct blows or yanking motions. Neither related to parental expectations, so Wilson needed to argue plain error on appeal. Wilson’s opening brief is at times unclear on the appropriate standard of review for each issue raised. Rather than stating the standard of review when discussing an argument, the brief lays out the general standards for preserved and unpreserved objections. Then, it describes the district court as having erred “reversibly and/or plainly” or having “erred and abused its discretion” for a general category of testimony. Aplt. Br. 9, 16. In fact, Wilson states that, because he “objected to Beeson’s testimony regarding ‘parental expectations’ and ‘medical diagnoses,’ the Court’s review of these errors is for harmfulness.” Id. at 25. What this fails to address is that Wilson only objected on certain grounds at trial: invasion 16  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 17 of the province of the jury. That is insufficient to capture his current Rule 16 argument. Wilson’s reply brief attempts to sidestep this omission. It states that the government misunderstands the structure of the opening brief and points to its catch- all discussion of standards of review in general, then the description of the alleged errors, and then a discussion of how all complained-of aspects of Dr. Beeson’s testimony as a whole would meet the plain-error standard. Conspicuously absent from the five-page discussion of plain error that Wilson points to is any reference to Rule 16, any indication as to whether he had objected below as required by 10th Cir. R. 28.1(A), and any analysis of how that alleged error was plain. Because Wilson did not preserve this objection and his appellate briefs fail to properly address the issue on plain error review, the claim is waived. c. Commenting on credibility Wilson’s final argument with respect to Dr. Beeson’s testimony is that she impermissibly commented on his credibility as a witness. Wilson recognizes on appeal that he failed specifically to object on these grounds below, so we review for plain error. We conclude that there was no error in permitting Dr. Beeson’s testimony. During Dr. Beeson’s testimony, the prosecution asked her whether B.W.’s injuries were consistent with hitting her face on someone’s collarbone, her mother rolling over on her, falling off of a bed, or being lightly stepped on. Dr. Beeson said the injuries were inconsistent with those explanations. Dr. Beeson explained that 17  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 18 injuries of the severity present in B.W.’s case were more likely caused by several forceful yanking actions and direct blows. Dr. Beeson also said the injuries were unlikely to have been caused by B.W. because at two months old, babies are not mobile and, therefore, are typically unable to cause injuries to themselves. Wilson now argues that this testimony was “in form and function” a comment on his credibility, which he says is impermissible. Aplt. Br. 23. Wilson is mistaken. Typically, expert witnesses are not permitted to “go so far as to usurp the exclusive function of the jury to weigh the evidence and determine credibility.” United States v. Hill, 749 F.3d 1250, 1260 (10th Cir. 2014) (quoting United States v. Samara, 643 F.2d 701, 705 (10th Cir. 1981)). This precludes testimony that “does nothing but” vouch for or cast doubt on another witness’s credibility and, therefore, does not “assist the trier of fact” in its credibility determinations. United States v. Charley, 189 F.3d 1251, 1267 (10th Cir. 1999) (en banc). That is not the case here. Dr. Beeson never commented on Wilson’s credibility. Rather, Dr. Beeson was explaining her diagnosis and rebutting any innocent explanation for B.W.’s injuries. Courts have consistently recognized that “[a] doctor can . . . summarize the medical evidence and express an opinion that the evidence is consistent or inconsistent with the victim’s allegations.” United States v. Whitted, 11 F.3d 782, 785 (8th Cir. 1993); see also Charley, 189 F.3d at 1264 (allowing doctor to “inform the jury of characteristics in sexually abused children and describe the characteristics the alleged victim exhibits” (quoting Whitted, 11 F.3d at 785)). The fact that this may have impacted Wilson’s credibility in the eyes of the jury is of no moment. If an accident 18  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 19 investigator stated that damage to a car and skid marks on the road could only have been caused by a car driving well above the speed limit and a defendant claimed to be driving below the speed limit, this may indeed lower the jury’s estimation of the defendant’s credibility. But this would not be grounds to exclude the accident investigator’s testimony and, in fact, represents only an effort to “assist the trier of fact” in its credibility determinations. To be sure, when a medical finding can be explained equally by abuse or an innocent explanation, a doctor’s “unconditional opinion,” Charley, 189 F.3d at 1266, that he or she believes “abuse has in fact occurred is ordinarily neither useful to the jury nor admissible.” Whitted, 11 F.3d at 785. That is because to believe the victim was abused, the doctor “had to believe [the victim’s] statements” and doctors are “not qualified to judge . . . truthfulness.” Id. at 786. Therefore, the doctor is “merely vouching for the credibility of the child complainants.” Charley, 189 F.3d at 1266. Again, that is not the case here. Dr. Beeson’s testimony spoke to symptoms and their causes, which rendered innocent explanations unlikely; it was not judging a party’s truthfulness nor choosing the victim’s account over an equally plausible explanation. There was no error, let alone plain error, in permitting the testimony. B. Lay Witness Testimony Next, Wilson challenges multiple aspects of Springer’s and Poffel’s testimony, as well as one aspect of Henson’s testimony. We will first address his argument that 19  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 20 Springer and Poffel gave improper expert testimony, and then we will address his argument that all three impermissibly commented on his credibility. a. Expert testimony Wilson argues that both Springer and Poffel, despite being admitted as lay witnesses, at times offered what was in effect expert testimony. Wilson objected to statements by both below, so we review for abuse of discretion. The district court overruled the objection as to Poffel and sustained the objection as to Springer; nevertheless, Springer went on to make further similar statements that the district court allowed without further objection. We conclude that, though the witnesses may have approached the line of expert testimony, any error would have been harmless. Lay witness opinion testimony is limited to statements that are “(a) rationally based on the witness’s perception; (b) helpful to clearly understanding the witness’s testimony or to determining a fact in issue; and (c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.” Fed. R. Evid. 701. Meanwhile, expert opinion testimony admitted via Rule 702 is meant to cover specialized knowledge, and experts must demonstrate that they are qualified to provide such opinions. Here, both Poffel and Springer were offered as lay witnesses who had interviewed Wilson and would testify as to their interactions with him. Yet, both Springer and Poffel made statements that appeared to be the result of specialized knowledge. Specifically, Springer stated that in his experience interviewing suspects, child abusers often proffer innocent explanations for the child’s injuries, minimize the extent of the injuries, and minimize their involvement 20  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 21 in those injuries. Similarly, Poffel said that it is common for perpetrators of child abuse to minimize the child’s injuries. Because “opinion testimony premised on the officer’s professional experience as a whole is expert testimony,” United States v. Cristerna-Gonzalez, 962 F.3d 1253, 1259 (10th Cir. 2020), Poffel and Springer’s statements may have crossed this line. See United States v. Beierle, 810 F.3d 1193, 1203 (10th Cir. 2016) (Hartz, J., concurring) (“A law-enforcement officer’s opinion based on police training and the experience of conducting hundreds of interviews easily fits that description.”). On the other hand, “observations [that] are common enough and require . . . a limited amount of expertise,” may be appropriate as lay witness testimony. James River Ins. Co. v. Rapid Funding, LLC, 658 F.3d 1207, 1214 (10th Cir. 2011) (quoting United States v. VonWillie, 59 F.3d 922, 929 (9th Cir. 1995)). Whether the observations at issue can be characterized as such is not entirely clear. “[T]he government concedes that a fraction of the answers did cross the line between Fed. R. Evid. 701 and 702.” Aple. Br. 35. That said, we need not conclusively determine whether the challenged statements were admitted in error because they were substantially similar to statements made by Dr. Beeson, who was admitted as an expert. (See ROA v.3 154- 56 (saying it is “[v]ery common” for suspected child abusers to offer accidental explanations and minimize their involvement, and that it is concerning if a parent’s retelling of a child’s medical history changes).) Therefore, even if Poffel’s and Springer’s statements were excluded, the jury still would have heard the same things. 21  Appellate Case: 24-7093 Document: 66-1 Date Filed: 09/09/2026 Page: 22 Wilson, then, was not prejudiced by the admission of Poffel’s and Springer’s challenged testimony. Finally, the last asserted ground of potentially errant expert testimony was Poffel’s testimony that when a suspect tells multiple different stories, it likely means they are lying. This does not qualify as specialized knowledge. The fact that “the changing of his story during the course of the interview” indicates dishonesty is a “fairly obvious and commonly understood issue[] of veracity.” Hill, 749 F.3d at 1262 (“The reason the issue of credibility ‘belongs to the jury’ is that jurors ‘are presumed to be fitted for it by their natural intelligence and their