Dr. Dennis is the Chair of the Division of Pre-Hospital and Emergency Services in the Department of Trauma & Burn at the Cook County Hospital in Chicago Il.  He is an Associate Professor of Surgery at Rush Medical College and Chairman of the Department of Surgery at Midwestern University College of Osteopathic Medicine

Dr. Dennis brings greater than twenty years of experience in public safety including extensive experience in the fire service, EMS and law enforcement.  He currently serves as the sworn Director of Medical Operations for the Illinois State Police, the Northern Illinois Police Alarm System and the Associate Medical Director for the Illinois State Police.  He is the author of "Officer Down, a practical tactical guide for surviving injury in the street" published by Kendall Hunt.  Dr. Dennis has been featured nationally on the National Geographic documentary "Chicago Trauma" and most recently on the CNN docu-series "Chicagoland".  He currently serves as Executive Medical Advisor on the NBC prime time shows, Chicago Med, Chicago Fire and Chicago PD.  Dr. Dennis is extensively published in both trauma and emergency medicine literature and regularly lectures around the globe.