(CNN) -- Homicide detectives outside Baltimore are investigating an apparent murder-suicide involving a police officer and a firefighter.
Three people were found dead inside a home in Glen Burnie, Maryland, early Sunday morning after a reported shooting around 1:35 a.m., police in Anne Arundel County said.
Police said the suspected shooter -- Christopher Lee Robinson, 37, a Baltimore police officer -- was one of the people found dead at the scene.
Baltimore firefighter Andrew Scott Hoffman, 27, and Marie Leanne Edith Hartman, 26, were killed.
"Preliminary investigation indicates that the suspect/shooter was one of the deceased and that he had a relationship with the female victim," police said.
Police said they were still investigating the shooter's motive, but described the shooting as a "domestic incident."
CNN's Rick Martin contributed to this report.
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