Nichols

IN THE UNITED STATES DISTRICT COURT

FOR THE SOUTHERN DISTRICT OF ILLINOIS

DEMETRIUS H. NICHOLS, deceased by )

and through DIANE JONES his sister and )

next best friend and Administrator of the )

Estate of DEMETRIUS H. NICHOLS, )

) Case No. 24-cv-796-SMY

Plaintiff, )

)

vs. )

)

WEXFORD HEALTH SOURCES, INC., )

DR. MOHAMMED Z. SIDDIQUI, )

N.P. ALI DEARMOND, and )

DR. STEPHEN RITZ, )

)

Defendants. )

MEMORANDUM AND ORDER

YANDLE, District Judge:

On January 28, 2021, Demetrius Nichols died while incarcerated at Menard Correctional

Center. Plaintiff Diane Jones, Administrator of the Estate of Demetrius Nichols, filed this action

against Wexford Health Sources, Inc. (“Wexford”), Dr. Mohammed Siddique, Ali Dearmond, NP,

and Dr. Stephen Ritz asserting violations of 42 U.S.C § 1983 and state law claims for survival and

wrongful death. Now before the Court is Defendants' Motion to Exclude Plaintiff's Expert Witness

(Doc. 134), which Jones opposes (Doc. 153). For the following reasons, the Motion is DENIED.

Legal Standard

Federal Rule of Evidence 702 provides for the admission of expert testimony that assists

the trier of fact to understand the evidence or to determine a fact in issue. Fed.R.Evid. 702. District

courts have a “gatekeeping” obligation to ensure that expert testimony is both relevant and reliable.

Fed. R. Evid. 702; Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (2003); Lees v.

Carthage College, 714 F.3d 516, 521 (7th Cir. 2013). Essentially, the Court must answer three

questions before admitting expert testimony: (1) is the expert qualified; (2) is the expert's

methodology reliable; and (3) will the expert's testimony assist the trier of fact in understanding

the evidence or determining a fact in issue. Myers v. Illinois Cent. R. Co., 629 F.3d 639, 644 (7th

Cir. 2010). The party offering the expert testimony bears the burden of proof as to relevance and

reliability. Brown v. Burlington N. Santa Fe Ry. Co., 765 F.3d 765, 772 (7th Cir. 2014) (citing

Lewis v. CITGO Petroleum Corp., 561 F.3d 698, 705 (7th Cir. 2009)).

“A Daubert inquiry is not designed to have the district judge take the place of the jury to

decide ultimate issues of credibility and accuracy.” Lapsley v. Xtek, Inc., 689 F.3d 802, 805 (7th

Cir. 2012). “If the proposed expert testimony meets the Daubert threshold of relevance and

reliability, the accuracy of the actual evidence is to be tested before the jury with the familiar tools

of “vigorous cross-examination, presentation of contrary evidence, and careful instruction on the

burden of proof.”” Id. (quoting Daubert, 509 U.S. at 596).

Discussion

Plaintiff retained Ryan D. Herrington, M.D., MPH to support her claims. Dr. Herrington

received his medical degree from the University of Virginia and a master’s degree in public health

from the Ohio State University. He is licensed to practice medicine and is dual board certified by

the American Board of Preventive Medicine in both public health/preventive medicine and

addiction medicine. Dr. Herrington has worked as a primary care physician and as a medical

director in correctional settings.

In this case, Dr. Herrington opines to a reasonable degree of medical certainty that: (1)

from an asthma perspective, Nichols would have benefitted from earlier referral to otolaryngology;

(2) Wexford practitioners’ repeated use of steroids for Nichols amounted to customary

maintenance treatment for his nasal polyps; (3) Wexford’s custom of using steroids for nasal

polyps was harmful for Nichols; (4) Wexford’s custom of using steroids for Nichols made it

increasingly likely that he would suffer an asthma exacerbation; and (5) Wexford’s failure to

provide Nichols a higher level of care on January 25, 2021 and on January 26, 2021 was a breach

of the standard of care.

Defendants argue Dr. Herrington’s opinions should be excluded because he seeks to opine

on matters outside of his area of expertise and failed to review sufficient facts and data to form

reliable opinions. Defendants further contend his opinions are not grounded in reliable

methodology. The Court disagrees.

Dr. Herrington has the requisite background and experience to render opinions regarding

the medical care Nichols received while incarcerated. He has over a decade of experience in

correctional medicine, including as a former medical director of a state prison. Dr. Herrington

testified that he was either directly or indirectly involved with every patient at those correctional

facilities. His experience renders him qualified to opine regarding the clinical and operational

duties at issue in this case.

Defendants also argue Dr. Herrington’s opinions are unreliable. In reaching his opinions,

Dr. Herrington reviewed relevant case materials, including medical records and deposition

testimony. He applied his extensive experience to evaluate the facts of this case and reached his

conclusions regarding the medical care provided to Nichols. Dr. Herrington’s report includes a

detailed methodology section in which he outlines and explains how he grounded his analysis in

the medical records and treatment chronology. Dr. Herrington referenced numerous sources he

relied on in formulating his opinions. While Defendants take particular issue with his reliance on

the Healthcare Monitor 4th Report in Lippert v. Jeffreys (“Lippert Report”), asserting the report is

inadmissible hearsay, relying on hearsay does not render an expert’s opinions unreliable for

Daubert purposes. See Tilstra v. BouMatic, LLC, 791 F.3d 749, 753 (7th Cir. 2015).

In sum, the reliability of data and assumptions used in applying a methodology is tested by

the adversarial process and determined by the jury; the court's role is generally limited to assessing

the reliability of the methodology — the framework — of the expert's analysis.” See Manpower, Inc.

v. Insurance Co. of Pennsylvania, 732 F.3d 796, 808 (7th Cir. 2013). Defendants’ disagreements

with Dr. Herrington’s ultimate conclusions are not a justifiable basis to exclude his opinions.

Defendants may certainly attempt to discredit Dr. Herrington on cross-examination or in their own

presentation of the evidence. But their arguments go to the weight to be given Dr. Herrington’s

testimony, not to its admissibility. See Daubert, 509 U.S. at 596. His opinions are relevant and

will assist the jury with its analysis of whether Defendants’ care fell below accepted practice and

caused or contributed to Nichols’ death. Therefore, Defendants’ Motion is denied.

IT IS SO ORDERED.

DATED: December 3, 2025 Ae MU Ge

STACI M. YANDLE

United States District Judge

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