State v. K. Proctor

07/14/2026 DA 23-0409 Case Number: DA 23-0409 IN THE SUPREME COURT OF THE STATE OF MONTANA 2026 MT 150 STATE OF MONTANA, Plaintiff and Appellee, v. KATHERINE ANNE PROCTOR, Defendant and Appellant. APPEAL FROM: District Court of the First Judicial District, In and For the County of Lewis and Clark, Cause No. CDC 2022-30 Honorable Kathy Seeley, Presiding Judge COUNSEL OF RECORD: For Appellant: Alexander H. Pyle, Assistant Public Defender, Office of the State Public Defender, Lewistown, Montana For Appellee: Austin Knudsen, Montana Attorney General, Cori Losing, Assistant Attorney General, Helena, Montana Kevin Downs, Lewis and Clark County Attorney, Mary Barry, Deputy County Attorney, Helena, Montana For Amici The American Civil Liberties Union and The ACLU of Montana: Alex Rate, ACLU of Montana Foundation Inc., Missoula, Montana For Amicus The Innocence Network: Karl Pitcher, Attorney at Law, Missoula, Montana  Submitted on Briefs: November 5, 2025 Decided: July 14, 2026 Filed: __________________________________________ Clerk 2 Justice Laurie McKinnon delivered the Opinion of the Court ¶1 Katherine Anne Proctor (Proctor) appeals her June 9, 2023 conviction for felony Assault on a Minor, in violation of § 45-5-212, MCA, entered in the First Judicial District Court, Lewis & Clark County. We affirm. ¶2 We restate the issues on appeal as follows: Issue One: Whether the District Court erred in admitting expert testimony related to “Shaken Baby Syndrome.” Issue Two: Whether the District Court erred by not suppressing evidence obtained under an impermissible general warrant. Issue Three: Whether the prosecutor violated Proctor’s right to a fair trial with impermissible statements related to Proctor’s character. Issue Four: Whether Proctor’s counsel was ineffective. FACTUAL AND PROCEDURAL BACKGROUND ¶3 P.P. was born in May 2021 and was healthy. At the time, Proctor was an Assistant Attorney General and P.P.’s father, Tim Proctor, was an officer with the Montana Highway Patrol. Proctor and Tim diligently participated in routine neonatal care for P.P. The family relied on an Owlet baby monitor integrated into a sock (Owlet) to track P.P.’s heart rate and oxygen levels at night. The family was then living in Helena, Montana, but were preparing to move to Choteau, Montana, for Tim’s job in August 2021. With Proctor primarily caring for P.P. in Helena, Tim began residing in the family’s new residence while returning regularly to assist Proctor. Unbeknownst to Proctor, Tim was engaged in an extramarital affair at this time. Proctor and Tim prepared to sell their house in Helena, with closing scheduled for September 29, 2021. However, Proctor could not immediately 3 move into the new Choteau home until her employer approved her to work remotely. Instead, Proctor would temporarily move into an apartment in Helena with P.P. Proctor enrolled P.P. with 3Rs Daycare (3Rs) in August 2021 so that she could return to work. Proctor also relied on extended family for supplemental childcare. ¶4 On September 7 and 9, 2021, workers at 3Rs noted P.P. had dime-sized bruises on her cheekbones and forehead when she arrived. P.P. arrived at day care with an abrasion on her nose on September 13, 2021. Tim took care of P.P. when she was sick with COVID-19 on September 20-23, 2021, and thereafter returned to Choteau. When Tim left, P.P. did not have a black eye. The next day, Proctor watched P.P. Tim returned to Helena on September 25, 2021, and noticed P.P.’s black eye, which Proctor claimed was the result of dropping a toy on herself. Two separate workers at 3Rs later testified about having seen P.P.’s black eye on September 27, 2021. The second worker was skeptical of Proctor’s proffered explanation because she had not seen P.P. demonstrate the dexterity required to grasp a toy in such a manner. ¶5 Tim returned to Helena on September 28, 2021, to assist Proctor in the final steps of vacating the Helena house. He picked up P.P. from 3Rs that evening and fed her a bottle at approximately 6:30 p.m. before leaving her on a blanket on the floor to continue packing the home with Proctor. Major Dustin Lerette (Lerette), one of Tim’s coworkers, arrived at around 7:45 p.m. and spoke with Tim. Lerette had a brief interaction with Proctor, who appeared “stressed.” Additionally, Lerette heard music and P.P. crying from inside the house. After Lerette left, Tim went back inside the house and found P.P. was asleep—not on the ground where he had last seen her—but in her car seat. Proctor remained packing 4 at the house and Tim took P.P. to the apartment for the night. Once there, Tim prepped P.P. for sleep, “put[ting] her pajamas on, chang[ing] her diaper[,]” and “warm[ing] up her bottle.” “The entire time[,]” P.P was asleep, only waking up “[a] little bit” for her evening bottle, of which she only consumed between “five and ten [milliliters].” P.P. usually consumed 125 milliliters. Tim woke at 1:30 a.m. on September 29, 2021, after hearing a noise. He checked on P.P., who remained asleep even after Tim picked her up. ¶6 At 6:00 a.m. on September 29, 2021, Proctor began readying P.P.’s morning bottle. P.P would not wake up. Data from the Owlet, worn by P.P. overnight, showed her heart rate had dropped to between 60 and 70 beats per minute (bpm). A typical four-month-old should register at least 100 bpm. The parents were concerned about possible seizure activity, as they noticed one side of P.P.’s body was twitching. Proctor called P.P.’s pediatrician, who advised bringing P.P. to the emergency room. ¶7 At the emergency room in Helena, medical personnel reacted quickly on P.P.’s arrival shortly after 7:00 a.m. because she was obviously “critically ill.” P.P. had a bruise on her right eyelid. Due to P.P.’s moist mucous membranes, emergency room Dr. Andy Coil (Dr. Coil) ruled out dehydration. Although P.P.’s heart rate and oxygen were initially normal, her oxygen levels dropped shortly after her arrival, necessitating supplemental oxygen. Her temperature was low. P.P was less responsive than she should have been at four-months-old. ¶8 Dr. Coil conducted a head-to-toe exam and found P.P.’s anterior fontanelle, the “top front part of [her] skull[,]” was “tense and bulging a little bit.” The swelling of P.P.’s anterior fontanelle, which should have been “normally soft and somewhat squishy” at 5 P.P.’s stage of development, indicated pressure on the brain. Dr. Coil stepped out of the room to order a computed tomography (CT) scan of the brain. When Dr. Coil returned, P.P. was actively seizing. The CT scan indicated P.P. had suffered “a large, massive anoxic brain injury.” Given the severity of the brain injury, Dr. Coil decided to transfer P.P. to another hospital capable of providing “pediatric neurosurgery, [. . .] pediatric neurology, and a pediatric intensivist” as required by P.P.’s dire situation but which was unavailable in Helena. P.P. spent five hours in the Helena emergency room before being transported by helicopter with Proctor to the children’s hospital in Kalispell, Montana. In preparation for the flight, Dr. Coil and staff placed P.P. in a “medically induced coma” and intubated her to “put her on life support to breathe” during transport.1 Dr. Coil indicated he would not have been surprised if P.P. died due to the severity of her injuries. ¶9 Dr. Nicholas Satovick (Dr. Satovick), a neuroradiologist who contracted with the hospital in Kalispell, reviewed P.P.’s CT scan from the Helena hospital. He found the scan reflected P.P. had “a small subdural hemorrhage” on the left side of her brain, a “linear focus of blood in the right lower cerebellum,” and a “profound [. . .] decreased attenuation of the cerebral hemispheres of the brain on both sides.” The latter diagnosis was determined because, rather than showing a “differentiation of gray and white matter” in P.P.’s brain, the scans reflected “all one shade of grey” indicating an injury such as “loss of blood flow or oxygen to the brain.” Dr. Satovick agreed with Dr. Coil that the CT scan 1 Medical staff made one unsuccessful attempt to intubate P.P. before completing the procedure. No evidence suggested P.P. had suffered any physical injury from the first failed attempt. 6 indicated P.P. had experienced a “hypoxic ischemic event” in which brain injuries were caused by reduced oxygen and blood flow. ¶10 When P.P. and Proctor arrived in Kalispell, Dr. Timothy Stidham (Dr. Stidham) ordered a Magnetic Resonance Imaging (MRI) scan of P.P.’s brain, a chest x-ray to check the intubation, and a blood test. The blood test ruled out a Sudden Infant Death Syndrome event. P.P. tested positive for the common cold but was not displaying any symptoms. She tested negative for COVID-19, influenza, and respiratory syncytial virus. P.P. began seizing again after metabolizing the antiseizure drugs administered before her flight to Kalispell. Dr. Stidham restabilized P.P. ¶11 The CT scan confirmed significant swelling on the brain as well as significant portions of her brain that were without oxygen long enough that she was going to have irreversible, significant injury. Dr. Stidham decided against surgery on the brain because all sides of the brain were affected, thus negating any benefit from emergency surgery. The MRI showed P.P. had a cervical ligamentous injury but no spinal cord injury in her neck. The subdural bleeding between the brain and the skull was more evident on the MRI than it appeared on the CT scan conducted in Helena. Dr. Stidham put a C-collar on P.P. to stabilize her neck ligaments and protect her spine. ¶12 Dr. Stidham asked Proctor about the bruising on P.P.’s face. He was skeptical of Proctor’s explanation that P.P. had dropped a toy on herself because “it’s kind of hard for four-months-olds to bruise their face and [. . .] bring [a] toy to her face with enough force to cause a bruise[.]” Dr. Stidham testified that “any bruising without a very consistent mechanism is a concern for [. . .] some type of child abuse[,]” especially in conjunction 7 with the x-ray imaging, which revealed multiple rib fractures. Dr. Stidham began to suspect P.P.’s injuries resulted from trauma, specifically non-accidental trauma or abusive trauma. He indicated the fractures were more important than the history of a mechanism for the bruises on P.P’s face, and his leading diagnosis was “non-accidental trauma” (NAT). On September 30, 2021, Dr. Stidham conducted a skeletal survey, which confirmed the rib fractures and a femur fracture. The fractures were in various stages of healing, suggestive of “different time points of different abusive injuries to [P.P.]” Dr. Stidham further opined the rib fractures and P.P.’s brain injuries suggested a diagnosis of NAT caused by inflicted abuse. ¶13 P.P.’s arrival presented a fast-moving medical situation to doctors in Kalispell, but Dr. Stidham managed to keep Proctor and Tim apprised of developments. On September 29, he first told the parents that P.P.’s injuries resembled “inflicted injuries.” Neither parent could provide Dr. Stidham with any history that could explain P.P.’s injuries and P.P. had no history of any significant trauma. Confronted with Dr. Stidham’s suspicions, Tim vomited. Proctor remained focused on the timing of P.P.’s injuries. ¶14 On October 1, 2021, Dr. Mark Remington (Dr. Remington), an ophthalmologist in Kalispell, examined P.P.’s right eye.2 Dr. Remington found extensive hemorrhages in the retina and “significant macular edema[,]” or swelling in the retina. When Dr. Remington conducted a second exam on October 19, 2021, he was able to examine both of P.P.’s eyes. 2 Dr. Remington only dilated P.P.’s right eye, keeping her left eye undisturbed so nurses could continue checking for a sudden increase in pressure on the brain, a symptom of which is a dilated pupil, due to a persisting intracranial hemorrhage. 8 The hemorrhages were clearing in P.P.’s right eye as expected, but he also discovered retinoschisis, or a splitting of the retina, as well as hemorrhages in the left eye. ¶15 Dr. Kelly Schmidt (Dr. Schmidt), a specialist in pediatric neurosurgery, also treated P.P. On October 6, 2021, Dr. Schmidt ordered another MRI, which showed a tearing of the arachnoid, a thin membrane connecting the brain to the skull. Blood from this tear mixed with brain fluid into P.P.’s subarachnoid space. P.P. could not reabsorb the fluid, which had begun to accumulate and cause pressure against P.P.’s skull in the week after she first entered the Kalispell hospital. According to Dr. Schmidt, this was a “classic” scenario in abuse cases: a patient would enter the hospital with a tear on this layer of the brain and, “anywhere from one to sometimes weeks later[,]” fluid would then accumulate within the brain. ¶16 Dr. Schmidt testified to child abuse protocols wherein doctors will examine both the brain and the spine. Because infants have weaker neck muscles, cases of “abusive head trauma or shaken baby” can lead to injury of the cervical spine. Babies “very rarely have bony injur[ies,]” and instead they “tend to have injury more to soft tissue and to ligaments.” The MRI of P.P.’s neck showed fluid in the joints of her neck at the base of her skull, indicating a disruption of those joints. According to Dr. Schmidt, this injury can only be caused by shaking a baby. As for a prognosis for P.P., Dr. Schmidt could only offer to Proctor and Tim that P.P.’s brain had been “irreversibly injured.” She emphasized the severity of P.P.’s brain injury. Further, she opined to them that P.P. “had been abused[.]” Proctor again questioned the timeline of P.P.’s injuries, a response Dr. Schmidt found 9 “unusual” given the severity of P.P.’s immediate situation and the rapid pace of treatment decisions. ¶17 Nine days after P.P.’s arrival in Kalispell, Dr. Schmidt relieved the continued-pressure on her brain by draining the fluid. After a couple days, the laceration healed and the tube was removed. However, P.P.’s recovery was limited to the abatement of more immediate dangers from her injuries; Dr. Schmidt opined that P.P. would require full-time care for the rest of her life and be unable to function independently in the world. P.P.’s brain injury liquified her brain and the injured areas were “replaced by the normal brain fluid,” leaving her with large portions of “just nonfunctioning brain.” P.P. was missing the vision-processing structures and the balance center in the cerebellum due to strokes she had been having. Dr. Schmidt was consistent in her diagnosis that P.P.’s brain injury was caused by non-accidental trauma, discounting a competing theory ascribing cause to a “venous clot” because the “strokes weren’t venous” since the issue was that “the brain didn’t get enough oxygenated blood from the arteries[,]” not an issue of the veins inability to drain blood away from the brain. Dr. Schmidt described that the result resembled “a near drowning.” Criminal Investigation ¶18 On September 29, Proctor called 3Rs to explain P.P.’s absence from daycare. P.P. had last attended on September 28, when staff noticed the bruises under P.P.’s eyes. At the time, a staff member asked Proctor about the injuries, which were blamed on dropping a toy. When Tim arrived to pick up P.P. that evening, he offered the same explanation. Out of concern for the bruising, 3Rs’s owner, Susan Anderson (Anderson) reviewed the 10 staff logbooks and discovered “a pattern of injuries” staff had noticed and kept a record of during P.P.’s attendance. In addition to the black eye, the pattern included an alleged “rug burn” on P.P.’s nose documented on September 13, 2021 and two additional bruises on September 7 and 9. On September 28, staff met to discuss P.P. and decided to report the pattern of injuries to Child Protective Services (CPS), which Anderson did on September 29.3 ¶19 Led by Detective Joshua Van Dyke (Van Dyke) of the Lewis & Clark Sheriff’s Office, the State began investigating the abuse of P.P. the same day. Van Dyke informed Tim of the investigation. Van Dyke seized two smartphones belonging to Proctor and Tim pursuant to a search warrant obtained on October 15, 2021. He applied for a second warrant to search the devices, which was granted on October 28, 2021. The warrant application alleged aggravated assault as probable cause and requested “[a]ll data currently stored in or related to the account or device identified herein related to the crimes or offenses identified herein[.]” This included location data, internet browsing history, media files, and any correspondence on the devices. Van Dyke averred “[c]riminals will often use [. . .] wireless communication methods to facilitate their crimes” but did not specify how wireless communication may have facilitated the alleged abuse of P.P. The warrant application sought cell phone information due to the parents’ use of the companion smartphone application for the Owlet monitor and further noted that, according to CPS 3 While in the Natal Intensive Care Unit, Proctor nicked P.P.’s finger with nail clippers, which should not be used on a child P.P.’s age. There were further concerns about the possibility of the wound becoming infected within the hospital environment. A hospital social worker reported this incident to CPS in addition to the report made by the day care. 11 worker Jennifer Blodgett (Blodgett), both Proctor and Tim were “on their phones for a significant amount of time following news of physical abuse to P.P.” At the suppression hearing, Van Dyke testified that Blodget confirmed the parents’ smartphone use to him; however Blodgett testified that she could not recall saying the same to Van Dyke. ¶20 The warrant granted the extraction of “all data currently stored” on the parents’ smartphones, with the exception of communications with legal counsel and clergy, as well as any information the parties stipulated to protecting. The data sought encompassed but was “not limited to” location history, internet activity, multimedia, metadata, and correspondence through associated applications. Proctor moved to suppress evidence obtained by this search warrant on the basis the warrant was overbroad. The District Court denied this motion, concluding the temporal limitations provided specificity and the data seized did not include “anything other than evidence related to the Owlet monitor, photos of P.P., and messages referencing P.P. or injuries to P.P.” Criminal Charges and Trial ¶21 The State filed an Amended Information on September 28, 2022, charging Proctor with Assault on a Minor, a felony in violation of § 45-5-212, MCA, alleged to have occurred between June 28, 2021 until October 13, 2021.4 Proctor, the State alleged, had been overwhelmed by balancing working and caring for P.P. with Tim largely absent. 4 The original Information, filed on January 24, 2022, charged Proctor with one count of Aggravated Assault and one count in the alternative of Accountability for Aggravated Assault. 12 ¶22 On March 4, 2022, Proctor moved to exclude testimony related to a series of diagnoses typically referred to as “shaken baby syndrome” (SBS), arguing SBS is based on insufficiently supported scientific evidence and its admission would be far more prejudicial than probative. The District Court held a hearing on the matter on August 26, 2022. ¶23 The State presented Dr. Kathryn Wells (Dr. Wells), a board-certified child abuse pediatrician, as their expert on NAT. She explained NAT, as a diagnosis, has been referred to by various names, including SBS and “Abusive Head Trauma” (AHT). Dr. Wells testified to the history of NAT, in addition to the controversies surrounding the diagnosis, particularly when referred to by different diagnostic names. Speaking to the more “colloquial term” of SBS, Dr. Wells noted that an SBS diagnosis does not result from a series of tests, but instead refers to a “constellation of medical findings.” Shaking “may be a component of [. . .] the mechanism that caused the injuries[,]” but the actual breadth of findings was more accurately captured by the terms AHT/NAT.5 Dr. Wells herself did not use SBS in her reports. Nevertheless, Dr. Wells testified that none of the major medical associations—namely the “American Medical Association, American Academy of Pediatrics, the radio graphic associations, the neurological associations”—disputed the validity of AHT as a medical diagnosis. AHT, according to Dr. Wells, presented a legal controversy, not a medical one. 5 AHT and NAT were used interchangeably by Dr. Wells. 13 ¶24 According to Dr. Wells, a doctor would arrive at an NAT diagnosis like any other: physical examinations of the patient, imaging, laboratory results, and the patient’s medical history, ruling out competing causes through a “differential diagnosis.” Dr. Wells explained the process of making a differential diagnosis: doctors begin with “a large list of things that may be a cause for a certain presentation” and narrow the list of possible causes as further tests are administered and doctors can interpret those results. ¶25 Helena doctors triaging P.P. initially diagnosed her with seizures, lack of oxygen, and brain injuries, which Dr. Wells opined was commensurate with the process of securing a differential diagnosis. Once P.P. transferred to Kalispell, treating doctors continued assessing her condition through blood tests, which eliminated a bleeding disorder as a possible cause for her condition, and administered further tests. A doctor arrives at a diagnosis based on what is assessed, and does not “speak to who did what” or the issue of culpability. Dr. Wells opined P.P.’s injuries were caused by “acceleration/deceleration” and “rotational inertial forces” due to the nonimpact type of injuries presented. P.P. had the triad of AHT injuries: retinal hemorrhages, brain bleeding, and brain swelling, consistent with acceleration/deceleration potentially caused by nonimpact or impact into a soft surface. However, she also had a brain contusion, a neck injury, and healing rib fractures consistent with squeezing or grabbing of the chest. Importantly, if only the triad was present, Dr. Wells would require further information to diagnose NAT. Taking the sum of all of P.P.’s symptoms and eliminating an infection, bleeding problem, or other underlying disorder through the differential diagnosis, Dr. Wells agreed P.P. had been abused. 14 ¶26 Discussion on NAT testimony continued at a September 20, 2022 hearing. Proctor presented testimony from Dr. John Galiznik to argue that a diagnosis of NAT based on retinal hemorrhages, brain bleeding, and brain swelling alone was unreliable without a differential diagnosis. The District Court then issued an oral order denying Proctor’s motion to exclude, concluding that, although a diagnosis based on that specific triad alone may not be reliable and “you have to have more to get [to an NAT diagnosis.]” The court was satisfied that an NAT diagnosis could be made on the evidence presented of the other injuries beyond the triad. The District Court concluded the method of diagnosing NAT was reliable and the experts were qualified to speak to that method. Thus, the State could present to the jury at trial evidence from expert witnesses and P.P.’s treating physicians on how, through the differential diagnosis process, medical staff arrived at an NAT diagnosis. ¶27 Trial began on December 5, 2022. The doctors who treated P.P. testified. The State presented Dr. Wells and Dr. Logan Dance (Dr. Dance), a radiologist, as experts. Dr. Dance opined that P.P. would have died from her brain injury if her skull had been fully fused and not been able to expand with the swelling of her brain. His analysis of P.P.’s imaging was not “diagnostic of abuse,” but rather fit with the mechanism of “severe noncontact shaking” resulting in bruising of the brain, a highly specific injury in cases of NAT not present in children accidentally injured in, for example, a car accident. As for P.P.’s neck injuries, Dr. Dance believed the fluid between the joints of the top two vertebrae at the base of her skull visible in the MRI scans indicated a loss of integrity to the connection between these bones consistent with deceleration and acceleration. P.P.’s femur fractures, according to Dr. Wells, most specifically suggested she had been abused, either through “really violent 15 shaking” or “just a yank” on her leg exerting significant force causing the end of the bone to separate from the growth plate. ¶28 Dr. Wells testified that the cartilaginous quality of infant rib bones renders them more difficult to fracture, requiring compression “front to back” or a “bending or fulcruming” force on the bones and suggesting a squeezing of P.P.’s ribs in conjunction with a shaking mechanism. For these reasons, Dr. Wells found the fractured ribs indicated abuse. As for the severe brain injury P.P. presented with on arrival at the Helena hospital, Dr. Wells and Dr. Dance agreed P.P. had been immediately injured sometime after her last “normal interaction[.]” This timeline suggested P.P. endured the most acute injury between the time Lerette conferred with Tim at 7:45 p.m. on September 28, 2021, when P.P. had been observed crying, and when Tim began to notice P.P.’s lethargy later that night. ¶29 Proctor’s experts testified to perceived deficiencies in the differential diagnosis and alternative interpretations of testing results. A clot in P.P.’s sagittal sinus vein, Dr. Julie Mack (Dr. Mack) and Dr. Joseph Scheller (Dr. Scheller) both opined, could have also caused P.P.’s brain injury but medical staff had not pursued a Magnetic Resonance Venography. The State countered this with Dr. Wells’ testimony that she had rarely encountered a sagittal vein clot and in those instances the clot resulted from abuse. Dr. Mack noted P.P.’s cerebellum laceration might have actually been a cerebellar cleft and thus the fluid in P.P.’s cerebellum was not caused by acceleration and deceleration. Dr. Scheller opined the fluid was caused by the failed intubation attempt, an assertion Dr. Coil, who had performed that procedure, categorically denied. 16 ¶30 As for the rib and femur fractures, Proctor’s expert disagreed with the State’s experts. Pediatric orthopedic surgeon Dr. Christopher Sullivan (Dr. Sullivan) believed the rib fractures were older and possibly caused during birth. Dr. Sullivan would have treated P.P.’s femur fractures through reconstructive surgery to reset her pelvis and then allowed the bones to heal in a body cast, a treatment plan Dr. Wells disagreed with because the fractures had occurred where the bone met cartilage and thus could heal on their own. Dr. Sullivan also posited that P.P. had rickets caused by a Vitamin D deficiency leading to brittle bones and Kalispell doctors had not tested for her Vitamin D levels. Dr. Dance did not find evidence of rickets in his review of P.P.’s imaging. ¶31 Evidence obtained from Proctor’s cell phone was also admitted. Van Dyke testified that data seized included Proctor’s use of the Pinterest application contemporaneously to P.P.’s time in the hospital, Proctor’s searches for defense counsel while P.P. was in the hospital, photographs of P.P. showing bruises and abrasions, and some correspondence with Tim. The latter consisted of a photo of P.P. and an accompanying message that she was “doing great” and a photo of P.P. outside. Other than noting he found her phone use incongruent with the severity of P.P.’s ordeal, Van Dyke did not elaborate any further on the meaning of Proctor’s phone activity. ¶32 At closing, the prosecutor reiterated the State’s theory of the case. She imagined Proctor’s predicament on the evening of September 28: extrapolating the pressures of being a new mom largely without Tim, the exhaustion of moving, and the anxiety clouding her ability to continue in her career if not approved for remote work. The prosecutor summarized P.P.’s life beginning at 7:00 a.m. on September 28 until she arrived at the 17 hospital in Helena at 7:00 a.m. on September 29: P.P. healthy despite a bruised eye at 3Rs; Tim bringing her home and giving her a bottle that evening; P.P. crying while her parents finished packing; P.P. quiet after Tim spoke to LeRette; P.P. consuming only some of her evening bottle; P.P. unresponsive at 1:00 a.m. when Tim picked her up, and finally her alarming condition on the morning of September 29. The prosecutor reminded the jury that P.P.’s injuries were caused not by one instance of violent shaking, although that appeared to cause the most significant brain injury. Rather, the prosecutor delineated, P.P. had experienced numerous fractures and bruising over an extended period of time. ¶33 The prosecutor then characterized Proctor’s behavior once P.P. had been admitted to the hospital. She first noted her preparation for the case as indicative of her own diligent character because “when people are under pressure [. . . ] their character really comes out.” This stood in contrast with Proctor’s text messages to Tim wherein she said the intubated-P.P. was “doing great” rather than focusing on P.P.’s predicament. The prosecutor cast aspersions on Proctor for using her phone to search for criminal defense attorneys instead of researching the complex medical terminology presented from P.P.’s doctors. ¶34 The jury returned a verdict finding Proctor guilty of assault on a minor. Proctor moved for a new trial, which the court denied on April 3, 2023. On June 9, 2023, the court sentenced Proctor to 20 years in the Montana Women’s Prison. Proctor now appeals. STANDARDS OF REVIEW ¶35 We review evidentiary rulings for an abuse of discretion. State v. Pelletier, 2020 MT 249, ¶ 12, 401 Mont. 454, 473 P.3d 991 (citations omitted). A court abuses its 18 discretion when it is based on a clearly erroneous finding of fact, an erroneous conclusion or application of law, or otherwise acts arbitrarily, without conscientious judgment or in excess of the bounds of reason, resulting in substantial injustice. Pelletier, ¶ 12 (citation omitted). ¶36 Whether or not a search warrant was overbroad is a legal conclusion which we review de novo. State v. Graham, 2004 MT 385, ¶ 11, 325 Mont. 110, 103 P.3d 1073. ¶37 Generally, this Court will not address issues of prosecutorial misconduct pertaining to a prosecutor’s statements not objected to at trial. State v. Haithcox, 2019 MT 201, ¶ 23, 397 Mont. 103, 447 P.3d 452; see also State v. Devereaux, 2022 MT 130, ¶ 21, 409 Mont. 177, 512 P.3d 1198; State v. Miller, 2022 MT 92, ¶ 10, 408 Mont. 316, 510 P.3d 17 (failure to contemporaneously object to an asserted error generally constitutes a waiver of the right to seek appellate review). However, this Court, in our discretion, may review an unpreserved assertion of error under the common law plain error doctrine. Devereaux, ¶ 21; Miller¸ ¶ 10. ¶38 Claims of ineffective assistance of counsel present mixed questions of law and fact which this Court reviews de novo. State v. Weber, 2016 MT 138, ¶ 11, 383 Mont. 508, 373 P.3d 26. DISCUSSION ¶39 Issue One: Whether the District Court erred in admitting expert testimony related to “Shaken Baby Syndrome.” ¶40 On appeal, Proctor argues the reasoning and methodology supporting SBS is not scientifically reliable or accurate and that recent modeling has not validated the hypothesis. 19 Moreover, she argues that P.P.’s case presents a non-impact mechanism and that the State had not adequately demonstrated the reliability of non-impact biomechanical principles of an SBS diagnosis. The State counters that her argument only obliquely captures the prosecution’s theory of the case, which relied on a diagnosis of NAT resulting from several possible mechanisms, including shaking P.P., and manifested in multiple severe injuries, including rib and femur fractures and injuries to her neck, indicating conduct beyond the classical non-impact SBS hypothesis. ¶41 Proctor and amicus, the Montana Innocence Project, rely on a New Jersey case to cast doubt on the reliability of an SBS diagnosis. There, the court held that the SBS hypothesis, also referred to as AHT, was unreliable due to a “lack of biomedical support[.]” New Jersey v. Nieves (Nieves I), 302 A.3d 595, 620 (N.J. Super. Ct. App. Div. 2023). The trial court barred the admission of expert testimony related to SBS/AHT in two separate criminal prosecutions and the state appealed. Nieves I, 302 A.3d at 599. In a consolidated appeal, the Appellate Division of the New Jersey Superior Court affirmed both decisions on the basis that, although the pediatric medical community accepted the validity of SBS/AHT, the theory itself “integrates multiple scientific disciplines” and thus its admissibility required the proponent of SBS/AHT to “establish cross-disciplinary validation to establish reliability.” Nieves I, 302 A.3d at 599. The expert testimony presented at the preliminary evidentiary hearings provided only a consensus of the existing “controversy surrounding the theory that the biomechanical principles underlying SBS/AHT actually supported the conclusion that shaking only can cause injuries associated with SBS/AHT.” Nieves I, 302 A.3d at 599. The specific “triad of symptoms” supporting 20 an SBS/AHT diagnosis included subdural hemorrhages, severe retinal hemorrhages, and encephalopathy, but these alone were “not diagnostic”; rather, “the combination of findings, in the absence of pathology,” provides the final diagnosis. Nieves I, 302 A.3d at 603. ¶42 The New Jersey Supreme Court affirmed this decision, holding that the expert testimony failed the general acceptance standard established in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923).6 State v. Nieves (Nieves II), 345 A.3d 1127, 1132 (N.J. 2025). The Frye standard requires expert testimony “not only be reliable, but its proponent must establish that the information to which the expert will testify is generally accepted in the relevant community to which the expertise belongs.” Nieves II, 345 A.3d at 1132. The defense experts in one of the underlying prosecutions evaluated on appeal “emphasized [the] lack of general acceptance of SBS/AHT” across relevant scientific disciplines. Nieves II, 345 A.3d at 1170. Thus, evidence of acceptance by the medical community notwithstanding, the State had “not met its burden of establishing general acceptance [of SBS/AHT] in the relevant scientific communities because the research, studies, and testimony presented at the [Frye] hearing reflect a lack of general acceptance by many in the biomechanical community regarding SBS/AHT without impact.” Nieves II, 345 A.3d at 1171-72. ¶43 However, Montana rejected the “general acceptance rule” aspect of the Frye test more than four decades ago because it no longer conformed “with the spirit of the new 6 New Jersey has since abandoned the Frye standard. Nieves II, 345 A.3d at 1132 n.1 (citing New Jersey v. Olenowski, 289 A.3d 456, 459 (N.J. 2023)). 21 rules of evidence.” Barmeyer v. Mont. Power Co., 202 Mont. 185, 193, 657 P.2d 594, 598 (1983) (citations omitted), overruled on other grounds Martel v. Mont. Power Co, 231 Mont. 96, 103, 752 P.2d 140, 145 (1988). “‘Absolute certainty of result or unanimity of scientific opinion is not required for admissibility.’” Barmeyer, 202 Mont. at 193, 657 P.2d at 598 (quoting United States v. Baller, 519 F.2d 463, 466 (4th Cir. 1975)). Granted, scientific advancements must have their “‘first day in court [. . .] [a]nd court records are full of the conflicting opinions of doctors, engineers, and accountants, to name just a few of the legions of expert witnesses . . . [but] . . . [u]nless an exaggerated popular opinion of the accuracy of a particular technique makes its use prejudicial or likely to mislead the jury, it is better to admit relevant scientific evidence in the same manner as other expert testimony and allow its weight to be attacked by cross-examination and refutation.’” Barmeyer, 202 Mont. at 193-94, 657 P.2d at 598 (quoting Baller, 519 F.2d at 466). Cross-examination is “the shield to guard against unwarranted opinions[.]” Barmeyer, 202 Mont. at 194, 657 P.2d at 598-99 (citation omitted). ¶44 Generally, all relevant evidence is admissible. State v. Santoro, 2024 MT 136, ¶ 19, 417 Mont. 92, 551 P.3d 822 (citing M. R. Evid. 402). Montana Rules of Evidence 701-705 additionally govern the admission of opinion and expert testimony. Santoro, ¶ 19. Rule 702 provides, “[i]f scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise.” The clause “or otherwise[,]” in the context of Rule 702, refers to testimony provided by an expert witness not necessarily “in the form of opinion, 22 but which informs the jury so they may render the correct decision.” M. R. Evid. 702, Commission Comments; State v. Jay, 2013 MT 79, ¶ 27, 369 Mont. 332, 298 P.3d 396; State v. Cassill, 70 Mont. 433, 448, 227 P. 49, 55 (1924). “To restate this rule, if a reliable field helps the trier of fact, and the court deems the witness qualified as an expert, then he may testify.” State v. Clifford, 2005 MT 219, ¶ 33, 328 Mont. 300, 121 P.3d 489 (emphasis in original). This Court has repeatedly stated the test for admissibility of expert testimony is whether the matter is sufficiently beyond common experience that the opinion of the expert will assist the trier of fact to understand the