There’s a tiny 27-acre island off the coast of Portsmouth, New Hampshire called Smuttynose Island. The population in 1873 was six. So it shocked the country when two of them were brutally murdered — an event that led to the publication of the book "Mystery on the Isles of Shoals," by J. Dennis Robinson. WSHU’s Davis Dunavin brings us the story as part of the podcast ‘Off the Path from New York to Boston.’ And a caution — this story contains disturbing details about two murders.