An FBI agent who was walking his dog shot and killed another dog that attacked his Schnauzer, in front of the woman and child walking it.

When the two dogs — and their walkers — encountered each other on Friday on opposite sides of a narrow pedestrian bridge in Glen Burnie, Md., the difference between the canines must have been obvious.

One was a 180-pound Great Dane. The miniature Schnauzer weighed just 15 pounds.

The humans attempted to communicate about how they would cross the bridge, Anne Arundel County police said. But then the Great Dane, a 4-year-old named Fynn who belonged to the daughter of the 62-year-old woman, broke away from the woman and her 4-year-old grandson and attacked the Schnauzer.

The FBI agent, who was off duty at the time, tried to separate his four-year-old dog, named Kirby, from Fynn, police said. But Kirby was in Fynn’s mouth, and the agent couldn’t pry them apart.

The agent shot Fynn twice, using his service weapon. Fynn died on the bridge, near Warbler Walk and Mockingbird Circle in the Tanyard Springs neighborhood.

Police said that the encounter is under investigation. They did not release the names of any of the dog walkers.

“I can’t tell you that we anticipate any charges,” Lt. T.J. Smith said, but the state’s attorney’s office is considering the matter.

Kirby was treated at a hospital for injuries, police said.