Maryland Gov. Larry Hogan said that there were "potentially" three people killed in a shooting in Smithsburg.
Hogan said police responded to the shooting and pursued the suspect.
"The suspect fired and shot a state trooper in the shoulder," Hogan said.
The trooper returned fire, according to Hogan.
The Washington County Sheriff's Office did not say whether the shooter was killed in the encounter. However, the agency said the suspect is "no longer a threat to the community."
Agents with the Bureau of Alcohol, Tobacco, Firearms and Explosives announced they are assisting with the response.