Federal, State, and Local Officials Test Mass Casualty Response in Maryland Exercise

BALTIMORE – U.S. Customs and Border Protection (CBP), alongside federal, state, and local partners, conducted a comprehensive homeland security exercise in Middle River, Maryland, on September 30, 2025, to evaluate and enhance interagency coordination and incident response capabilities. Operation Harbor Shield, as the drill was named, involved approximately 375 participants, including law enforcement personnel and medical professionals, simulating responses to two distinct active shooter scenarios.

The exercise, a key component of the Department of Homeland Security’s Homeland Security Exercise and Evaluation Program, was designed to identify potential deficiencies in capabilities, communication systems, equipment interoperability, and overall preparedness. The scenarios presented were intended to create a high-stress environment for responders, testing their decision-making and ability to manage complex emergencies. The two simulated events included an active shooter incident within a seaport building and a more complex attack involving an active shooter and a drone-deployed improvised explosive device at a concert venue.

Planning and coordination for Operation Harbor Shield were managed by U.S. Customs and Border Protection, the University of Maryland Medical Center, and the U.S. Air Force Center for the Sustainment of Trauma and Readiness Skills (C-STARS) in Baltimore. A broad coalition of agencies participated, including CBP, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), Maryland State Police, Maryland Transportation Authority (MDTA) Police, Baltimore County Police, Baltimore County Fire, and Baltimore City Police. These organizations worked in tandem to simulate a cohesive response to a major incident.

Medical professionals from the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center were integral to the exercise, receiving simulated casualties via ground transport and medevac helicopters. This allowed for the evaluation of their Trauma Resuscitation Unit and provided responders with hands-on training in critical life-saving care techniques. The exercise also incorporated training sessions for first responders focused on tactical and trauma care, covering areas such as incident command, weapons handling, room and stairwell clearing, triage procedures, and advanced wound management, including tourniquet application and airway management.

To further enhance the realism of the scenarios, approximately 125 volunteers acted as building occupants and concertgoers, portraying various injury levels to simulate the chaos and urgency of a mass casualty event. The U.S. Army’s Combat Capabilities Development Command Army Research Laboratory provided its Gracie’s Quarters training site for the exercise. The successful execution of such exercises is vital for the nation’s preparedness, offering a critical opportunity to refine planning, validate existing capabilities, and pinpoint areas requiring improvement in the collective response to large-scale emergencies. Residents can be assured that such exercises contribute to a more robust and coordinated emergency response system designed to protect communities.

Article by Mel Anara, based upon information from U.S. Customs and Border Protection.

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