Why is the Little Compton, Rhode Island area so murdery, by episodes?

Little Compton is in the far south-eastern corner of Rhode Island, in Newport County, forty-five minutes from Providence and an hour and a quarter from Boston. It was Sakonnet land before twenty-nine Massachusetts settlers arrived with a charter, and the name is usually read as 'where the water pours forth'. In 1999 it had roughly 3,500 residents, a median age of fifty-three and a reputation as an affluent, unspoiled New England town where many people did not lock their doors.

The Little Compton area's two cases are twenty-four years and twenty-one miles apart, both in the southern half of the smallest state: one in Little Compton itself, one in South Kingstown. Neither episode has a crowd of victims. Each adds a single murder, so the total is two episodes. Episode 139 goes back to May 1999, to a sixty-six-year-old widow living alone in a house she was having extended. Episode 55 goes back to May 1975, to a South Kingstown neighbourhood where children played outside until the street lights came on, and to a family with three children aged ten, seven and five.