Teetz v. Sedgwick County, Kansas et al

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF KANSAS
MARQUAN TEETZ, as Next Friend and
Personal Representative of the ESTATE OF
CEDRIC LOFTON, deceased,
Plaintiff,
v. 	Case No. 22-1134-EFM
JASON STEPIEN, et. al.,
Defendants.
MEMORANDUM AND ORDER
Before the Court are eight Daubert motions. Defendants Jason Stepien, Brenton Newby,
Karen Conklin, William Buckner, and Benito Mendoza (collectively “Defendants”) move to strike
or exclude the opinions of Plaintiff’s experts, including Dr. Jane Turner (Doc. 249), Dr. Alon
Steinberg (Doc. 250), Jerome Davis (Doc. 251), and Dr. Michael Lyman (Doc. 252). Plaintiff
moves to strike Defendants’ experts, including Dr. Robert Bux (Doc. 253), Dr. Bill Geis (Doc.
254), Dr. Mark Kroll (Doc. 255), and Dr. Richard Hough (Doc. 256).
On December 8, 2025, the Court held a Daubert hearing during which the Court heard
testimony from two of Defendants’ experts and arguments from counsel on all eight experts. The
Court made several rulings from the bench on most of the motions but reserved its ruling on the
motions concerning Dr. Lyman and Dr. Kroll. This Order rules on those two motions and
memorializes the Court’s rulings on the remaining Daubert motions as detailed below.
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I. 	Factual and Procedural Background1
On September 24, 2021, Wichita Police Department (“WPD”) officers placed 17-year-old
Cedric Lofton, a foster child, in a WRAP restraint device after Lofton resisted WPD officers’
attempts to take him to the hospital for a mental health evaluation. WPD officers transported
Lofton to the Sedgwick County Juvenile Intake and Assessment Center (“JIAC”). At JIAC, Lofton
was released from the WRAP restraint and continued to exhibit symptoms of a mental health crisis,
leading to a subsequent physical confrontation between Lofton and Defendants. Defendants, JIAC
and Sedgwick County Juvenile Detention Facility (“JDF”) officers, placed Lofton in a prone
restraint and maintained the prone restraint for 35–40 minutes. At some point, Defendant Stepien
called 911, Lofton became unconscious, and EMS arrived. EMS triaged Lofton as code blue (no
pulse, no breathing), attempted life-saving measures, and transported Lofton to Wesley Medical
Center. Lofton was pronounced dead two days later on September 26, 2021. Dr. Timothy Gorrill,
the Sedgwick County District Coroner, performed an autopsy of Lofton and concluded that Lofton
died because of complications of cardiopulmonary arrest sustained after physical struggle while
restrained in the prone position.
The underlying circumstances surrounding Lofton’s death, and the cause thereof, are the
subject of eight experts’ reports presently before the Court. Two of these experts’ reports, Jerome
Davis and Dr. Michael Lyman, were previously before the Court on Defendants’ Daubert motions
at the summary judgment stage.2 The parties fully briefed the present matters, and the Court held
a Daubert hearing on all eight experts on December 8, 2025.
1 The Court previously documented the uncontroverted facts in this case at the summary judgment stage. See
Teetz ex rel. Lofton v. Stepien, 2024 WL 4381342, at *1–5 (D. Kan. Oct. 3, 2024), aff'd, 142 F.4th 705 (10th Cir.
2025). Thus, the Court proceeds summarily with the facts here, which are taken from the Pretrial Order.
2 Teetz ex rel. Lofton v. Stepien, 2024 WL 4381229, at *1 (D. Kan. Oct. 3, 2024).
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II. 	Legal Standard
Federal Rule of Evidence 702 governs the admissibility of opinion testimony from
witnesses qualified as experts by their knowledge, skill, experience, training, or education. Under
Rule 702, expert opinion testimony is admissible to assist the fact finder in matters of scientific,
technical, or otherwise specialized knowledge provided that such testimony (1) is based upon
sufficient facts or data, (2) is the product of reliable principles and methods, and (3) the witness
applied the principles and methods reliably to the facts of the case.3 As these requirements
demonstrate, the Court is charged as a gatekeeper to admit only expert testimony that is relevant
and reliable.4 Consideration of proffered expert testimony is a flexible inquiry, specific to the facts
of the case at bar.5 The party offering the expert testimony bears the burden of showing that the
expert’s testimony is admissible.6
III. 	Analysis
At the Daubert hearing, the Court first addressed Plaintiff’s motions because Defendants
presented witness testimony from two of their experts. Here, the Court addresses the motions in
the order they were filed, beginning with Defendants’ Daubert motions.
3 Fed. R. Evid. 702.
4 See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 589 (1993).
5 Id. at 593; see also Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 150 (1999) (rejecting formulaic
application of reliability factors discussed in Daubert because “[t]oo much depends upon the particular circumstances
of the particular case at issue”).
6 Myrick v. Husqvarna Prof’l Prods., 508 F. Supp. 3d 846, 854 (D. Kan. 2020).
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A. 	Defendants’ Daubert Motions
1. 	Dr. Jane Turner
First, Defendants move to strike the opinions of Dr. Jane Turner. Dr. Turner is forensic
pathologist who conducted a second autopsy of Lofton, reviewed relevant evidence, and read Dr.
Alon Steinberg’s publications—one of Plaintiff’s other experts. Defendants challenge Dr. Turner’s
opinions that (1) “it is far more likely than not that the extensive hemorrhaging in [Lofton]’s back
and shoulders was the result of such significant force applied by [Defendants];” (2) “[t]he absence
of offensive wounds . . . confirms [Lofton] was not the aggressor;” and (3) “the cause of Cedric
Lofton’s death is prone restraint with cardiac arrest.”7 The Court addresses the admissibility of
each challenged opinion in turn.
Defendants argue that Dr. Turner’s first opinion regarding the cause of Lofton’s injuries is
unreliable. Specifically, Defendants argue that Dr. Turner failed to adequately account for another
potential cause: the altercation where WPD officers placed Lofton in a WRAP restraint to transport
him to JIAC. Dr. Turner reviewed the body camera footage of the WRAP altercation and
deposition transcripts of the WPD officers involved.8 While Dr. Turner’s report does not discuss
the previous WRAP altercation in detail, her opinion attributing the cause of injuries to Defendants
is not absolute, rather it is that Defendants are more likely than not the cause. The Court permits
Dr. Turner to opine as such, and any deficiency in her consideration of the WRAP altercation may
be sufficiently addressed in cross-examination.9
7 Doc. 249, Ex. M at 3.
8 Id. at 2.
9 See Daubert, 509 US. at 596 (“Vigorous cross-examination, presentation of contrary evidence, and careful
instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible
evidence.”).
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Next, Defendants argue that Dr. Turner’s second opinion that Lofton was not the aggressor
is directly contradicted by undisputed facts, pointing to video evidence that shows Lofton punching
Defendant Stepien in the face. Plaintiff argues Defendants “cherry-pick” Dr. Turner’s opinion, and
that the full context of Dr. Turner’s opinion demonstrates that Lofton was not resisting while in
the prone restraint since he lacked the offensive wounds that would normally accompany such
resistance. To that end, Dr. Turner may opine that the lack of offensive wounds is inconsistent
with someone who is resisting. But because “an expert opinion cannot be based on facts that are
contradicted by undisputed evidence,”10 Dr. Turner may not opine that Lofton “was not the
aggressor.”
Lastly, Defendants argue that Dr. Turner’s cause of death opinion lacks any reliable
methodology because it relies solely on Dr. Steinberg’s opinions and publications. As Plaintiff
points out, an expert “may rely on the opinions of another expert if they inform or contribute to
his own independent conclusion.”11 But an expert “may not simply parrot or recite the opinions
and knowledge of other expert and fact witnesses.” 12 Thus, the Court permits Dr. Turner to offer
her cause of death opinion to the extent it is based on her own review of this case.
Overall, the Court grants in part and denies in part Defendants’ motion regarding Dr.
Turner’s opinions according to the parameters discussed above.
2. 	Dr. Alon Steinberg
Second, Defendants move to strike or exclude the opinions of Dr. Alon Steinberg. Dr.
Steinberg is a cardiologist who has testified in matters concerning prone restraint death. Dr.
10 Doe v. Lewis Roca Rothgerber Christie LLP, 2025 WL 2815641, at *4 (D.N.M. Sept. 30, 2025).
11 Ash Grove Cement Co. v. Emps. Ins. of Wausau, 246 F.R.D. 656, 661 (D. Kan. 2017).
12 Id.
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Steinberg wrote an initial report for this case after reviewing various documents. Dr. Steinberg
also wrote a rebuttal report after reviewing three of Defendants’ experts’ reports. Defendants
challenge Dr. Steinberg’s opinions that (1) concern the cause of Lofton’s injuries and rebut Dr.
Bux, Defendants’ expert, on the issue; (2) rebut Dr. Geis, Defendants’ expert; and (3) the delay in
administering CPR contributed to Lofton’s death.
The parties’ briefing and the Court’s rulings on other experts at issue largely moots
Defendants’ challenges to Dr. Steinberg. Plaintiff will not offer Dr. Steinberg to testify as to the
cause of Lofton’s injuries or to rebut Dr. Bux on that matter. Instead, Plaintiff offers Dr. Turner to
make that opinion under the parameters of the Court’s ruling above. Additionally, as explained
below, the Court bars Dr. Geis from testifying in this case and, therefore, any rebuttal by Dr.
Steinberg is unnecessary. Further, Plaintiff does not offer Dr. Steinberg to testify that the delay of
administering CPR contributed to Lofton’s death, so the Court bars Dr. Steinberg’s causation
opinion on this matter. Defendants indicate that whether Dr. Steinberg may discuss the delay of
administering CPR generally will be the subject of a future motion in limine, but that is a question
for another day. Thus, the Court grants Defendants’ motion and bars Dr. Steinberg from offering
his opinions challenged by Defendants’ motion.
3. 	Jerome Davis
Third, Defendants move to strike or exclude the opinions of Jerome Davis. This is
Defendants’ second attempt to do so. Mr. Davis has over 30 years of working in correctional
environments in both adult and juvenile facilities with expertise in use of force and restraints. After
reviewing video footage and other documented evidence, Mr. Davis offers eight opinions in this
case. Defendants challenge each opinion in Mr. Davis’s report. Plaintiff concedes that Opinions
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1–3, 5, and 7–8 13 are barred by the Court’s previous ruling prohibiting experts from testifying to
legal conclusions or are otherwise irrelevant to the remaining Defendants in this case. Plaintiff,
however, asserts that Opinions 4 and 6 are admissible. The Court addresses the admissibility of
these opinions in turn.
In Opinion 4, Mr. Davis opines that Defendant Stepien “unnecessarily aggressed Lofton.” 14
Defendant argues that this opinion is simply a repackaged legal conclusion barred by the Court’s
previous ruling. The Court agrees and bars Mr. Davis from offering this opinion at trial.
In Opinion 6, Mr. Davis opines that “[t]he dangers associated with prone restraint were
well known within the juvenile justice community” prior to the events underlying this case.15
Defendants first argue Mr. Davis is unqualified to opine on the juvenile justice community’s
knowledge of prone restraint dangers because he is not a medical doctor. Mr. Davis, however, does
not opine on whether such knowledge is medically accurate. Next, Defendants argue that Mr.
Davis does not sufficiently tie the juvenile justice community’s general knowledge to Defendants’
personal knowledge, rendering his opinion unhelpful to the jury. But Mr. Davis’s opinion will help
the jury determine what Defendants may or may not have known as members of the juvenile justice
community and evaluate their credibility. Lastly, Defendants argue that Mr. Davis’s testimony
alludes to claims that are no longer a part of this case and will mislead the jury. But the claims
13 When discussing Opinion 7 at the Daubert hearing, Plaintiff seemingly argued that he should be able to
offer Mr. Davis’s opinions on Defendants’ training (or lack thereof) and indicated such argument may be the subject
of a future motion in limine. Opinion 7, however, largely goes to Plaintiff’s failure-to-train claim against Sedgwick
County, which the Court previously dismissed. See Teetz v. Bd. of Cnty. Comm’rs of Sedgwick Cnty., Kan., 2023 WL
7698030, at *6–10 (D. Kan. Nov. 15, 2023). Plaintiff concedes as much in his written response. See Doc. 263 at 6
(“Plaintiff’s failure to train claim against [Sedgwick] County was dismissed by the Court on the pleadings, and,
therefore, is not at issue in trial. Accordingly, Plaintiff will not be offering Mr. Davis for this opinion at trial.”). Thus,
the Court bars Mr. Davis from offering Opinion 7 at trial.
14 Doc. 251, Ex. A at 9.
15 Id. at 10.
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remaining against Defendants necessarily require the jury to determine what a reasonable officer
would have done in this case; Mr. Davis’s opinions speak to this inquiry. Thus, the Court permits
Mr. Davis to offer Opinion 6.
Overall, the Court grants in part and denies in part Defendants’ motion regarding Mr.
Davis’s opinions according to the parameters discussed above.
4. 	Dr. Michael Lyman
Finally, Defendants move to strike or exclude the opinions of Dr. Michael Lyman. This is
Defendants’ second attempt to do so. Dr. Lyman holds a Ph.D. in Higher and Adult Education, is
a former law enforcement agent, and has expertise in police procedures. He offers testimony about
national standards on prone restraint use and that Defendants’ use of the prone restraint violated
JIAC policy. Defendants challenge Dr. Lyman’s opinions for various reasons. The Court addresses
each of Defendants’ reasons in turn.
Defendants first challenge Dr. Lyman’s qualification to testify to national standards in this
case, arguing his expertise lies in policing, not juvenile corrections. But Dr. Lyman has significant
expertise on police use of force generally and has been permitted to testify in numerous cases on
corrections practices. Defendants do not identify any meaningful difference between standards on
prone restraint use in a corrections setting versus prone restraint use in a general policing setting.
Thus, Defendants’ challenge to Dr. Lyman fails on this ground.
Defendants also challenge Dr. Lyman’s opinion for lacking adequate foundation because
his opinions are largely grounded on the International Association of Chiefs of Police non-binding,
model policy and an advocacy piece. Defendants also point to Dr. Lyman’s deposition testimony
where he declares that the prone restraint is banned “everywhere,” but could only name two
specific jurisdictions. While the support Dr. Lyman’s opinions rely on may be shaky, any
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deficiencies can be sufficiently challenged on cross-examination. Accordingly, the Court permits
Dr. Lyman to offer his opinions on national standards. The Court, however, bars Dr. Lyman from
testifying to any impermissible legal conclusions or that Defendants violated JIAC policy and
national standards.
Overall, the Court grants in part and denies in part Defendants’ motion regarding Dr.
Lyman’s opinions according to the parameters discussed above.
B. 	Plaintiff’s Daubert Motions
1. 	Dr. Robert Bux
Turning to Plaintiff’s Daubert Motions, Plaintiff first moves to strike the opinions of Dr.
Robert Bux. Dr. Bux is a board-certified pathologist and M.D. whose report discusses “excited
delirium.”16 Excited delirium “is broadly defined as a state of agitation, excitability, paranoia,
aggression, and apparent immunity to pain, often associated with stimulant use and certain
psychiatric disorders.”17 Defendants seek to offer Dr. Bux’s opinion that Lofton was in a state of
excited delirium at JIAC based on Lofton’s exhibitions of continual resistance, extreme strength,
hyper-aggression, and profuse sweating. Plaintiff moves to exclude Dr. Bux’s opinion for various
reasons. The Court addresses each of Plaintiff’s reasons in turn.
Plaintiff begins by arguing that excited delirium is a controversial medical opinion that is
not accepted by the medical community, citing the American Medical Association, World Health
Organization, and the American Psychiatric Association, amongst others, as not recognizing it.
While these entities may not recognize excited delirium, it has been recognized and supported
16 See Doc. 253, Ex. 1 at 7–10.
17 Mann v. Taser Int’l., Inc., 588 F.3d 1291, 1299 n.4 (11th Cir. 2009).
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elsewhere within the scientific community for years.18 Several courts have permitted testimony
about excited delirium despite its controversial nature.19 Thus, Plaintiff’s arguments on the
controversy surrounding excited delirium are better suited for cross-examination over exclusion.20
Similarly, Plaintiff’s argument that Dr. Bux’s opinion is unreliable because this case does
not involve the use of illicit drugs is also better suited for cross-examination. Defendants concede
that excited delirium cases often involve the use of illicit drugs and there was no evidence that
Lofton used illicit drugs. But Defendants point out that excited delirium can also involve
individuals suffering from severe mental health issues and crises. There are several witness
observations 	of 	Lofton’s 	erratic 	behavior, 	and 	Plaintiff 	himself 	asserts 	that 	Lofton 	was
undoubtedly suffering a mental health crisis at JIAC. Excited delirium in such cases may be rare
but are not without scientific support. Plaintiff may sufficiently challenge Dr. Bux’s opinion as
novel on cross-examination.
Lastly, Plaintiff lodges several critiques against Dr. Bux’s methodology as applied to this
case, all of which are better suited for cross-examination over exclusion. Plaintiff argues that Dr.
Bux inconsistently testifies as to what characteristics must be present to diagnose excited delirium,
but his testimony on what characteristics Lofton exhibited is largely consistent with medical
18 Plaintiff concedes that excited delirium has past support but argues that there is a trend in the law departing
from it. This trend, however, largely seems to be a departure from using terminology associated with excited delirium,
in various contexts, not a departure from recognizing it as a valid diagnosis or syndrome. See Int’l Ass’n of Chiefs of
Police; Excited Delirium 1 n.1 (2017); see also James R. Gill, The Cancelling of Excited Delirium, 45 Am. J. Forensic
Med. & Pathology 98, 100 (2024).
19 Todero v. Blackwell, 2021 WL 4472550, at *2 (S.D. Ind. Sept. 30, 2021) (collecting cases).
20 Indeed, while Plaintiff discusses at length the controversy surrounding excited delirium in his written
motion, Plaintiff does not explicitly move to strike Dr. Bux on this ground. See Doc. 253 at 12 (“[A]ccepting for
present purposes that excited delirium is theoretically appropriate in some cases, Dr. Bux’s methodology here is not
reliable and not reliably applied to the facts of this case.” (emphasis in original)).
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literature supporting a diagnosis of excited delirium.21 Plaintiff also argues Dr. Bux lacks
foundational support for the characteristics he identified Lofton exhibited, but Dr. Bux permissibly
relied on witness testimony and video footage at the scene to reach these conclusions.22 Further,
Plaintiff argues that Dr. Bux failed to properly rule out the prone restraint itself as a cause of death,
but Dr. Bux explains why he concludes the prone restraint did not cause Lofton’s death in his
report.23 Thus, the Court permits Dr. Bux to offer his cause of death opinion, and any deficiencies
in methodology or foundation may be sufficiently addressed on cross-examination. Accordingly,
the Court denies Plaintiff’s motion as to Dr. Bux.
2. 	Dr. Bill Geis
Second, Plaintiff moves to strike the opinions of Dr. Bill Geis. Dr. Geis is a clinical
psychologist and conducted a psychological autopsy of Lofton. A psychological autopsy is a post-
mortem investigative procedure where an expert examines the decedent’s medical records and
interviews persons who interacted with the decedent before death to reconstruct the decedent’s
psychological state prior to death.24 Dr. Geis reviewed Lofton’s post-mortem medical records,
depositions of Lofton’s family members and the individual Defendants, and relevant video footage
to reconstruct Lofton’s psychological state prior to his death. In his report, Dr. Geis opines in
Opinion 1 that Lofton “was suffering from an acute psychotic condition,” showed signs of “the
emergence of the mental illness schizophrenia,” and that the most appropriate diagnosis of Lofton
21 See Phillipe Gonin et al., Excited Delirium: A Systematic Review, 25 Acad. Emergency Med. 552, 561
(2018) (“The criteria most frequently cited are hyperaggressive behavior with superhuman strength and a combative
attitude toward the police, hyperactivity, bizarre behaviors, unusual pain tolerance, and hyperthermia. However, these
criteria do not occur with equal frequency and none of them appear to be mandatory.” (emphasis added)).
22 See Fed. R. Evid. 703 (“An expert may base on opinion on facts or data in the case that the expert has been
made aware of or has personally observed”).
23 Doc. 253, Ex. 1 at 12–13.
24 See Bevan v. Valencia, 2018 WL 3187356, at *5 (D.N.M. June 28, 2018) (citation omitted).
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would be “Schizophreniform Disorder” based on the length of Lofton’s symptoms.25 In Opinion
2, Dr. Geis opines that Lofton’s “state of exhaustion and adrenalin overload must be considered
when assessing the cause of death.”26 Plaintiff largely challenges Dr. Geis’s opinions as based on
an unreliable methodology under Rule 702(c) and (d).
But Dr. Geis’s opinions are primarily flawed under Rule 702(a) because neither will “assist
the trier of fact to understand the evidence or determine a fact in issue.”27 As for Opinion 1, there
is no dispute that Lofton was suffering from a mental health crisis at the JIAC facility. Defendants
conceded at the Daubert hearing that labeling this crisis as “an acute psychotic condition,”
“schizophrenia,” or “Schizophreniform Disorder” makes no material difference. Thus, Opinion 1
is simply not helpful. The same is true for Opinion 2. Telling the jury that Lofton’s exhaustion and
adrenalin overload must be considered when evaluating cause of death tells the jury nothing,
particularly when other experts in this case considered these factors to evaluate Lofton’s cause of
death and the jury will generally be instructed to consider all the evidence presented in making its
factual findings. Accordingly, the Court grants Plaintiff’s motion and excludes Dr. Geis from
testifying.
3. 	Dr. Mark Kroll
Third, Plaintiff moves to strike the opinions of Dr. Mark Kroll. Dr. Kroll is a biomedical
scientist who has authored dozens of peer-reviewed articles on chest compression, resuscitation,
and restraint physiology, including the prone restraint. Dr. Kroll offers several opinions based on
the evidence in this case. Primarily, he opines that Defendants’ use of the prone restraint did not
25 Doc. 254, Ex. 1 at 27.
26 Id.
27 Fed. R. Evid. 702(a).
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contribute to Lofton’s death. Plaintiff challenges Dr. Kroll’s opinions for various reasons. The
Court addresses each of Plaintiff’s reasons in turn.
a. 	Plaintiff’s Challenges to Dr. Kroll’s Opinions as Contrary to Law and Based
on Irrelevant Studies
Plaintiff first moves to strike Dr. Kroll entirely, arguing his opinions are contrary to law.
Expert opinions contrary to law are generally inadmissible and should be excluded.28 Plaintiff’s
argument that Dr. Kroll’s opinions are contrary to law lie in the Tenth Circuit’s appellate ruling
affirming the Court’s denial of qualified immunity to Defendants at the summary judgment stage.29
Given the procedural posture of the case, the Tenth Circuit viewed the evidence in the light most
favorable to Plaintiff as the non-moving party.30 Plaintiff cites several statements from the Tenth
Circuit’s opinion:
Indeed, the use of a prolonged prone restraint after a defendant is subdued
constitutes deadly force which is justified only in limited circumstances under our
precedent.31
While we conclude that Mr. Teetz has met his burden to show a constitutional
violation, it is also true that the use of the prone restraint under these circumstances
constituted deadly force.32
[A]lthough the limited use of a prone restraint to obtain control of a suspect can be
proper police procedure, we have long recognized that prone restraints can
constitute deadly force if prolonged.33
28 See Southard v. United Reg'l Health Care Sys., Inc., 2008 WL 4489692, at *2 (N.D. Tex. Aug. 5, 2008)
(“[W]here . . . the expert’s opinion is based on an erroneous legal premise, it is appropriate to exclude such
testimony.”); see also Loeffel Steel Prods., Inc. v. Delta Brands, Inc., 387 F. Supp. 2d 794, 806 (N.D. Ill. 2005)
(“Expert opinions that are contrary to law are inadmissible.”).
29 Teetz, 142 F.4th at 731.
30 Id. at 719.
31 Id. at 722.
32 Id. at 725.
33 Id. at 726.
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A reasonable officer would have been on notice that continued application of
pressure after Mr. Lofton was subdued created a serious risk of asphyxiation and
death, even if he was still verbalizing threats. Under those circumstances, it is
clearly established that a continued prone restraint is unconstitutional.34
Here, Mr. Kroll’s opinions are not so contrary to the Tenth Circuit to be inadmissible.
Although the Tenth Circuit may have held that the prone restraint here constituted deadly force, it
did not go so far to hold that Defendants’ use of the prone restraint caused Lofton’s death or his
injuries. Nor could the Tenth Circuit do so, considering the procedural posture of the case. Thus,
Dr. Kroll’s opinion that the prone restraint did not contribute to Lofton’s death does not contravene
the Tenth Circuit. Additionally, the Tenth Circuit’s conclusion that Defendants’ prolonged use of
the prone restraint was unreasonable and unconstitutional is contingent on the jury’s determination
of the length of Lofton’s resistance, which is a material dispute in this case.35 And whether
Defendants placed substantial or significant pressure to Lofton’s back is also a material dispute
the jury must resolve.36 Thus, Dr. Kroll’s opinions regarding these material disputes do not
contravene Tenth Circuit precedent.
However, the Court cautions Defendants in light of the Tenth Circuit’s rulings. Dr. Kroll
has opinions he can offer that are not incompatible with those rulings, but those opinions require
skillful precision. He must be cautious that his testimony not vary from the Tenth Circuit’s actual
precedential statements regarding prone restraint, including its rulings in this very case. Should
34 Id. at 731.
35 See id. at 728–29 (“[T]he jury could find that Defendants imposed a prone restraint for as much as thirty
minutes, during which stagnant moments for as long as twelve minutes indicate Mr. Lofton had ceased resisting.
Under those facts, if proved, the use of deadly force was unreasonable and unconstitutional.” (internal quotation marks
and emphasis omitted) (emphases added)).
36 Id. at 716, 718 (noting this Court’s finding of a material factual dispute regarding the amount of weight
Defendants placed on Lofton).
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Dr. Kroll’s opinions at trial stray beyond those parameters, Defendants risk the Court’s at-trial
reconsideration of this ruling.
Additionally, the Court will not permit Dr. Kroll to offer his opinion on the “media myth”
of prone restraint dangers to the extent it relies on studies conducted on COVID-19 patients. These
studies are irrelevant to the situation in this case, which involved a healthy 17-year-old, not a
patient suffering from COVID-19 related pneumonia. Dr. Kroll’s opinion lacks an analysis or an
explanation on how these studies apply to Lofton. Thus, the Court bars Dr. Kroll from offering his
opinion that prone restraint dangers are a “myth” as based on these irrelevant studies.
b. 	Plaintiff’s Challenges to Dr. Kroll’s Qualifications and Helpfulness
Plaintiff next argues that Dr. Kroll is unqualified to opine that the prone restraint did not
contribute to or otherwise cause Lofton’s death because he is not a medical doctor. Lacking a
medical degree, however, does not automatically render Dr. Kroll unqualified so long as he has
the requisite experience and knowledge to form his opinions. Dr. Kroll is a biomedical scientist,
has authored dozens of peer-reviewed articles on chest compression and restraint physiology, and
bases his opinion on decades of research on how external forces affect breathing and cardiac
function. Other courts have found Dr. Kroll is sufficiently qualified to offer similar lack of
causation opinions as within his expertise.37 Dr. Kroll’s opinion that the prone restraint did not
contribute to Lofton’s death is well within his expertise. Thus, the Court permits Dr. Kroll to offer
this opinion.
37 See, e.g., Estate of Carlock v. Wiliamson, 2012 WL 75765, at *2–3 (C.D. Ill. Jan. 10, 2012) (permitting
Dr. Kroll to opine on the physical effects on prone restraint despite lacking a medical degree); Silva v. Chung, 2019
WL 2195201, at *4–5 (D. Haw. May 21, 2019) (collecting cases); but see Lackey v. City of Wilson, 2024 WL 21594,
at *2 (E.D. Okla. Jan. 2, 2024) (excluding Dr. Kroll from testifying because “Defendants have not carried their burden
to show that Dr. Kroll’s Opinions are admissible by a preponderance of the evidence.”).
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Plaintiff’s remaining challenges to Dr. Kroll attack his qualifications to testify to certain
opinions or his helpfulness to the jury in doing so. The Court addresses these challenges summarily
below:
• 	The Court bars Dr. Kroll from discussing compression asphyxia and flail
chest as irrelevant to the facts of this case.
• 	The Court permits Dr. Kroll to discuss how there was no genetic testing for
channelopathy related mutations because it is relevant rebuttal material to
Plaintiff’s cause of death theory.
• 	The Court permits Dr. Kroll to offer opinions based on his factual
assumptions regarding the amount of time Lofton was in the prone
restraint—uncuffed and cuffed—so long as he clearly represents these
opinions are based on his personal understanding of the facts.
• 	The Court bars Dr. Kroll from offering his opinions that “the prone restraint
of Mr. Lofton was necessary for handcuffing” and that “[t]he JIAC/JDF
officers had Mr. Lofton in the safest position he could be in given the
circumstances” as police practices opinions are beyond his expertise.
• 	The Court permits Dr. Kroll to offer his opinion on Defendant Newby’s use
of the wall as within his expertise, so long as he clearly represents this
opinion is based on his personal understanding of the facts.
• 	The Court permits Dr. Kroll to offer his opinion that “[t]he homicide manner
of death opinion is largely arbitrary” as within his expertise based on his
recent, peer-reviewed study on homicide manner of death rulings.
Overall, the Court grants in part and denies in part Plaintiff’s motion regarding Dr. Kroll
according to the parameters discussed above.
4. 	Dr. Richard Hough
Finally, Plaintiff moves to strike opinions of Dr. Richard Hough. Dr. Hough holds a Ph.D.
in Education and has expertise in police and corrections practices. Dr. Hough offers 19 opinions
in this case. Plaintiff’s written motion attacks Dr. Hough’s opinions in two ways: (1) Opinion 12
is unreliable and unhelpful; and (2) Dr. Hough, as a non-medical doctor, is unqualified to discuss
or opine on medical issues. At the Daubert hearing, the Court asked Plaintiff to clarify which
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opinions he believed Dr. Hough is unqualified to offer. Plaintiff identified Opinions 1–3 and 15.
The Court addresses the admissibility of each challenged opinion in turn.
The parties conceded that Opinions 1–2 are irrelevant to this case at the Daubert hearing.
Thus, the Court bars Dr. Hough from offering Opinions 1–2.
In Opinion 3, Dr. Hough opines that “the designation of homicide by a medical examiner
is not synonymous with legal terminology that connotes criminal intent or negligence.”38 The
Court concludes Dr. Hough is sufficiently qualified to opine as such based on his significant
experience and expertise in law enforcement practices.
In Opinion 12, Dr. Hough opines that Defendants’ restraint of Lofton was “reasonable”
based on the circumstances.39 Plaintiff attacks this opinion as unreliable and unhelpful, but the
parties conceded Opinion 12 is an impermissible legal conclusion at the Daubert hearing. Thus,
the Court bars Dr. Hough from offering Opinion 12.
Overall, the Court grants in part and denies in part Plaintiff’s motion regarding Dr. Hough’s
opinions according to the parameters discussed above.
IT IS THEREFORE ORDERED that Defendants’ Motion to Strike or Exclude Opinions
of Dr. Jane Turner (Doc. 249) is GRANTED in part and DENIED in part.
IT IS FURTHER ORDERED that Defendants’ Motion to Strike or Exclude Opinions of
Dr. Alon Steinberg (Doc. 250) is GRANTED.
IT IS FURTHER ORDERED that Defendants’ Motion to Strike or Exclude Opinions of
Jerome Davis (Doc. 251) is GRANTED in part and DENIED in part.
38 Doc. 256, Ex. 1 at 20.
39 Id. at 22.
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IT IS FURTHER ORDERED that Defendants’ Motion to Strike or Exclude Opinions of
Dr. Michael D. Lyman (Doc. 252) is GRANTED in part and DENIED in part.
IT IS FURTHER ORDERED that Plaintiff’s Daubert Motion to Strike Defense Expert
Robert M. Bux, M.D. (Doc. 253) is DENIED.
IT IS FURTHER ORDERED that Plaintiff’s Daubert Motion to Strike Defense Expert
Bill D. Geis, Ph.D. (Doc. 254) is GRANTED.
IT IS FURTHER ORDERED that Plaintiff’s Daubert Motion to Strike Defense Expert
Mark Kroll, Ph.D. (Doc. 255) is GRANTED in part and DENIED in part.
IT IS FURTHER ORDERED that Plaintiff’s Daubert Motion to Strike Defense Expert
Richard Hough (Doc. 256) is GRANTED in part and DENIED in part.
IT IS SO ORDERED.
Dated this 15th day of December, 2025.
ERIC F. MELGREN
UNITED STATES DISTRICT JUDGE
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