For Sergeant Heath Mahlmann, investigating a fire often means searching through burned debris for evidence that may be difficult for a person to find. Since 2020, he has had a partner with a very different investigative tool: Roxy, his specially trained fire-investigation canine.
Mahlmann joined the State Fire Marshal’s Office (SFMO) in 2015 after 23 years with the City of Brenham, where he worked on a fire truck and in the fire marshal’s office. In 2019, he transitioned to SFMO’s canine division and was paired with Roxy.
Born in the Netherlands in 2017, Roxy received her initial training in Alabama before coming to SFMO. Although she already knew the odors she was trained to detect, Mahlmann and Roxy spent several months developing their partnership.
“She knew the odor she was supposed to find,” Mahlmann said. “We just had to basically dial in her work ... and for us to be able to understand each other.”
Supporting fire investigations across Texas
Since beginning field work in 2020, the pair has worked approximately 550 fire scenes.
Roxy is trained to detect 14 odors associated with ignitable liquids, including gasoline, diesel, kerosene, and charcoal lighter fluid. At a fire scene, she follows an odor to its strongest source and holds her nose over it until Mahlmann gives her the command to return for her reward, a toy that, for Roxy, is essentially her paycheck.
“Her toys are her paycheck,” Mahlmann said. “All she wants to do is work, find the odor and get paid her toy.”
Keeping Roxy’s skills sharp requires regular training. Mahlmann trains with her throughout the year using different amounts of odor on surfaces such as wood, cardboard, clothing, and the ground. The pair also completes annual certification on all 14 odors in different scenarios.
Roxy’s precision has even earned her some bragging rights. At an annual canine conference, teams compete in “Closest to the Pin,” where dogs must locate a tiny amount of ignitable-liquid odor. Roxy won the competition in 2023, locating the source within approximately an eighth inch.
Life at home with an SFMO Canine
While Roxy is all business on a fire scene, Mahlmann says she has a very different personality off duty.
“She has what we call a switch,” he said. “When we put on her vest and get in a truck, she knows it’s work time.”
At home, Roxy is simply part of the family. SFMO’s canine handlers care for their dogs 24 hours a day, seven days a week.
For Mahlmann, Roxy’s value is clearest at a fire scene, where her ability to detect odors can help investigators find evidence they otherwise might miss.
“She provides a valuable service,” he said. “She’s very valuable on just about every scene.”
After hundreds of investigations, Roxy has become more than a canine partner. She’s family.
