Why is Elkridge, Maryland so murdery?

Elkridge is the oldest settlement in Howard County, a suburban town of about 16,750 people on the Patapsco River, roughly twenty minutes outside Baltimore. Its history begins with a 1652 treaty and a tobacco landing where each plantation had a wharf to load ships bound for England. James and Jimmie introduce it by working forward from there, and by giving the zip code.

The 26 murders arrive in five episodes, and only one is set in Elkridge itself: six victims between 1979 and 1989, mostly wealthy elderly people, none of them robbed. The other four sit 19 to 25 miles out, in Cape St. Claire, Middle River, Largo and Bethesda, a spread of Maryland suburbs. Two episodes carry seven victims each, so no single case does all the heavy lifting, and the dates run from the seventies through to 2008.

Worth saying plainly: this counts the show's cases, not the town's crime rate. The show picks the towns, and Elkridge happens to sit in a busy corner of Maryland.