08/18/2026
Retired Accelerant Detection K9 Zorro Passes Away
STATEWIDE (August 18, 2026) - The Office of the State Fire Marshal is mourning the loss of retired Accelerant Detection Canine Zorro, who passed away on July 26 after a career dedicated to serving the citizens of Maryland alongside his handler, Deputy Chief State Fire Marshal John Nelson.
For more than eight years, Zorro and Nelson were nearly inseparable. Together, they responded to fire scenes throughout Maryland and assisted investigators in Pennsylvania, Delaware, Virginia, and the District of Columbia, including an investigation at the White House. Their work helped investigators identify ignitable liquids and contributed to numerous arson investigations and convictions.
Through countless public education demonstrations, community events, school visits, camps, and open houses, Zorro met thousands of people. With his friendly personality and unmistakable enthusiasm for his work, he became an ambassador for the Office of the State Fire Marshal. He helped children and adults better understand the work of fire investigators and the important role that accelerant-detection canines play in solving arson cases.
A black Labrador retriever, Zorro was born in Mexico and began his journey as a working dog through Puppies Behind Bars in New Jersey, a program in which incarcerated individuals raise and train service and working dogs. He was later selected by the Bureau of Alcohol, To***co, Fi****ms and Explosives (ATF) for its Accelerant Detection Canine Program.
Nelson and Zorro became partners in 2016 and graduated together from ATF Accelerant Detection Canine Class #117 that December. Zorro was trained to detect trace amounts of ignitable liquids, including gasoline, kerosene, and lighter fluid, that could indicate a fire was intentionally set.
During Zorro's initial ATF training, one of Nelson's classmates captured a close-up photograph of Zorro intensely working an odor along the ground. What began as a candid photograph of a young detection canine learning his craft would go on to become a widely shared image demonstrating the remarkable ability and focus of accelerant detection canines. The photograph has been used extensively over the years and now hangs inside the ATF National Canine Training Center in Front Royal, Virginia — a lasting image of Zorro doing what he loved most: working.
As an ATF food-reward canine, Zorro received every meal directly from Nelson's hand as part of his daily training. Over their eight years together, Nelson estimated Zorro was rewarded more than 130,000 times, creating a partnership and bond that extended well beyond their work.
"For the last 18 years, a working dog has been part of my life, and the bond you develop with these dogs is difficult to put into words," Nelson said. "Zorro was truly one of a kind. He loved working, never met anyone he didn't like, and had a personality that made him unforgettable. Some of my greatest memories will always be watching him interact with children and families at community events. I will forever be grateful for the experiences, friendships, and memories Zorro gave my family and me. He was my partner, but more importantly, he was part of our family."
Zorro retired from active service on December 31, 2024, after more than eight years of service, spending the remainder of his life with Nelson and his family.
Zorro was Nelson's second ATF Accelerant Detection Canine. His first partner, K-9 Charlie, served from 2008 until retiring in 2016 and passed away in 2018. Together, Charlie and Zorro represented nearly two decades of Nelson's service to the ATF Accelerant Detection Canine Program and the Office of the State Fire Marshal.
"Zorro's service cannot be measured only by the number of fire scenes he worked or the cases he helped investigators solve," said Acting State Fire Marshal Jason M. Mowbray. "Anyone who has worked alongside a K-9 team understands they are more than investigative tools. They are partners, members of our agency family, and, most importantly, members of their handler's family. Our hearts are with John and his family as they say goodbye to a loyal partner."
