I remember the term ‘Travelers’ being used in reference to such crimes.
“Travellers” is the name for gypsies in Ireland, where they have protected status as an official ethnic group:
https://en.wikipedia.org/wiki/Irish_Travellers
There are significant groups of Travellers in the USA, including NY, PA, SC, and TX, where they often engage in home construction scams. One of their sources of income is to buy life insurance policies on their “blood relatives,” which can number in the hundreds or more because of inbreeding:
http://www.slate.com/articles/news_and_politics/explainer/2002/09/what_is_an_irish_traveler.html
https://www.irishcentral.com/culture/who-are-the-irish-travellers-in-the-us