Police were conducting a welfare check at the houseboat, which was docked at the Charlestown Marina, when they found the body of Joseph Donohue, 65, police said.

A 24-year-old named a “person of interest” in connection with the death of a man on a luxury houseboat in Charlestown now faces a murder charge, prosecutors said Thursday. Nora Nelson was arrested at the scene of the man’s death on Sunday night on a trio of warrants charging her with a variety of domestic violence offenses unrelated to the Charlestown case.

Nora Nelson of Boston has been charged with murder after a man was found stabbed to death on a Charlestown houseboat.