Why is Chappaqua, New York so murdery?

Chappaqua is a hamlet of about 3,000 people in Westchester County, half an hour or so outside New York City, tucked inside the town of New Castle. James and Jimmie set the scene with the Quakers who settled it in the 1730s and the tornado that flattened much of it in 1904, then got to the case that happened in the town itself.

The thirteen murders here are spread over six episodes in six towns, all within twenty-five miles: Chappaqua itself, then Demarest, Ramsey, Redding, Westport and Fair Lawn filling out the ring around the northern edge of the city. The dates run from 1962 to 2006, so this is not one grim year but the show coming back to the same comfortable commuter ground again and again.

One episode, episode 78, carries five of the thirteen; the rest are singles and pairs, so the total is mostly many cases adding up rather than one atrocity. Worth saying plainly: this counts the show's cases, not the local crime rate. The show picks the towns, and it keeps picking these.