Police charged a man in the fatal shootings of a Maryland couple.

Officers obtained an arrest warrant Monday for 56-year-old Kirk Matthews charging him with two counts of second-degree murder in the deaths of 44-year-old Linda McKenzie and 48-year-old Leslie Smith, Anne Arundel County Police detectives said.

The couple, who lived on a houseboat, were found in the road June 1, police said. They had been shot.

All three knew one another, police said, and the homicides were the result of an argument.

Matthews has been held at the Anne Arundel County Detention Center since June 3 on unrelated charges.