Untress “Trez” Quinn is a seasoned trial lawyer, focusing his practice on representing clients in disciplinary hearings in health care and educational settings, health care internal investigations, and the defense of medical malpractice and other catastrophic loss lawsuits. He has defended multiple complex litigation cases in both state and federal courts involving civil rights, product liability, medical malpractice and wrongful death claims. He has also represented health care clients under investigation by federal and state agencies and in the review of internal policies to conform with best health care practices. Untress’ defense of high-stakes litigation matters in both Illinois and Missouri have included matters involving mental health/suicide, neurological, obstetrical, neonatal, pediatric, cardiothoracic, gastroenterological and other traumatic injuries and losses. He also has specific experience defending medical professionals in matters alleging federal Section 1983 violations.

Untress leverages his experience as a registered nurse, along with experience in both direct patient care and health care administration, to skillfully counsel his clients through difficult health care-related matters.

His wide-ranging experience and abilities include representing health care providers in not only litigation matters, but also internal investigations involving:

  • Peer Review Hearings
  • Licensure denial or revocation
  • CMS suspensions or revocations
  • Administrative actions
  • Investigative demands received from federal and state agencies

Further, Untress is a frequent speaker at industry events across the nation, where he educates his clients and other professionals on various legal topics, and further advocates on their behalf. Active in firm leadership, he is managing attorney of the firm’s Edwardsville office and serves on the Inclusion Committee.


Prior to joining Armstrong Teasdale, Untress spent roughly 15 years in private practice at St. Louis area law firms. In his most recent role, he served as team leader for his prior firm’s Correctional Medicine industry team where he managed and supervised a team attorneys and paralegals.

Untress was a registered nurse for more than 10 years, and has been involved in the health care industry for over 25 years in total. Untress has extensive experience in both medical and surgical settings, including interventional radiology, ventilator rehabilitation, emergency room and cardiothoracic and neurological intensive care units. In addition to providing direct patient care, he served as a director of medical-surgical services, as well as a supervisor of interventional radiology and health care administrator. Untress also served as an adjunct professor at a local university teaching a class involving the interplay between health care and the law. Untress’ extensive medical knowledge and experience are assets he uses in the successful representation of his clients.

Untress was also a member of the U.S. Air Force Reserves for 13 years, where he achieved the rank of first lieutenant and was awarded the Meritorious Service Award. He was an honor graduate at the 3790th Medical Service Squadron for Medical Service Specialists at Sheppard Air Force Base in 1990.


  • Saint Louis University School of Law  (J.D., 2006)
    • Certificate in Health Law
    • Health Law Association
    • Black Law Student Association
  • National Louis University  (B.S., 2001)
    • Management
    • Dean’s List
    • Student Body Representative
  • Lutheran Medical Center School of Nursing  (R.N., 1994)
    • Salutatorian
    • Dean’s List
    • Student Body Representative
    • Alumni Academic Scholarship


  • Illinois
  • Missouri
  • U.S. District Court, Southern District of Illinois
  • U.S. District Court, Central District of Illinois
  • U.S. District Court, Eastern District of Missouri

Professional Activities

  • Leadership Council on Legal Diversity (LCLD) Fellow (2022)
  • Bar Association of Metropolitan St. Louis (BAMSL) (Board Secretary, 2021-2022)
  • Illinois Association for Defense Trial Lawyers, Diversity Committee Chair
  • St. Clair County Bar Association
  • American Bar Association
  • American Health Lawyers Association
  • U.S. District Court for the Southern District of Illinois (Merit Retention Panel, 2012; Magistrate Judge Selection Committee, 2018)
  • Attorney Registration and Disciplinary Commission of the Supreme Court of Illinois (Hearing Board Member)

Charitable and Civic Involvement

  • St. Clair County Child Advocacy Center (Member, Board of Directors)
  • Illinois Center for Autism in Fairview Heights, Illinois (Past Member, Board of Directors)
  • Student Nurse Achievement Program (SNAP) at Southern Illinois University (Past Member)
  • Illinois State Senator James F. Clayborne, Jr., Mentor Program (Past Mentor)
  • Office of the Inspector General / Illinois Department of Human Services Quality Care Board (Past Member)


  • The Best Lawyers in America®, Health Care Law (2023); Medical Malpractice Law - Defendants, Product Liability Litigation - Defendants (2024-present)
  • Distinguished Member Award, Illinois Defense Counsel (2022)
  • Savoy Magazine’s 2022 Most Influential Black Lawyers
  • Selected to The National Black Lawyers Top 100 in 2015
  • NAACP’s 54th Freedom Fund Awards for Excellence in Law
  • Leading Lawyer in the categories of Employment Law: Management; Medical Malpractice Defense Law; Personal Injury Defense Law: General; and Product Liability Defense
Contact Us
  • Worldwide
  • Boston, MA
  • Chicago, IL
  • Denver, CO
  • Dublin, Ireland
  • Edwardsville, IL
  • Jefferson City, MO
  • Kansas City, MO
  • Las Vegas, NV
  • London, England
  • Miami, FL
  • New York, NY
  • Orange County, CA
  • Philadelphia, PA
  • Princeton, NJ
  • Salt Lake City, UT
  • St. Louis, MO
  • Washington, D.C.
  • Wilmington, DE
abstract image of world map
Boston, MA
800 Boylston St.
30th Floor
Boston, MA 02199
Google Maps
Boston, Massachusetts
Chicago, IL
100 North Riverside Plaza
Suite 1500
Chicago, IL 60606-1520
Google Maps
Chicago, Illinois
Denver, CO
4643 S. Ulster St.
Suite 800
Denver, CO 80237
Google Maps
Denver, Colorado
Dublin, Ireland
Fitzwilliam Hall, Fitzwilliam Place
Dublin 2, Ireland
Google Maps
Edwardsville, IL
115 N. Second St.
Edwardsville, IL 62025
Google Maps
Edwardsville, Illinois
Jefferson City, MO
101 E. High St.
First Floor
Jefferson City, MO 65101
Google Maps
Jefferson City, Missouri
Kansas City, MO
2345 Grand Blvd.
Suite 1500
Kansas City, MO 64108
Google Maps
Kansas City, Missouri
Las Vegas, NV
7160 Rafael Rivera Way
Suite 320
Las Vegas, NV 89113
Google Maps
Las Vegas, Nevada
London, England
Royal College of Surgeons of England
38-43 Lincoln’s Inn Fields
London, WC2A 3PE
Google Maps
Miami, FL
355 Alhambra Circle
Suite 1200
Coral Gables, FL 33134
Google Maps
Photo of Miami, Florida
New York, NY
7 Times Square, 44th Floor
New York, NY 10036
Google Maps
New York City skyline
Orange County, CA
19800 MacArthur Boulevard
Suite 300
Irvine, CA 92612
Google Maps
Philadelphia, PA
2005 Market Street
29th Floor, One Commerce Square
Philadelphia, PA 19103
Google Maps
Philadelphia, Pennsylvania
Princeton, NJ
100 Overlook Center
Second Floor
Princeton, NJ 08540
Google Maps
Princeton, New Jersey
Salt Lake City, UT
222 South Main St.
Suite 1830
Salt Lake City, UT 84101
Google Maps
Salt Lake City, Utah
St. Louis, MO
7700 Forsyth Blvd.
Suite 1800
St. Louis, MO 63105
Google Maps
St. Louis, Missouri
Washington, D.C.
1717 Pennsylvania Avenue NW
Suite 400
Washington, DC 20006
Google Maps
Photo of Washington, D.C. with the Capitol in the foreground and Washington Monument in the background.
Wilmington, DE
1007 North Market Street
Wilmington, DE 19801
Google Maps
Wilmington, Delaware