Why is St. Johns, Arizona so murdery, by murders?

St. Johns sits in the White Mountains in north-east Arizona, with the New Mexico line a short drive from town. It is a small town of around 3,500 people, spread over 26 square miles, and the sort of place where a 155% population jump between 1970 and 1980 still gets mentioned. A large power plant built nearby gets the credit.

The town started life as San Juan. In 1879 a Mormon land agent bought land and water rights from a freight hauler who had built a bridge over the Little Colorado River, then found the same ground had already been sold to 17 Mexican families who had lived there for years. The two groups resented each other and fought for years. Two claims on one water supply is a reliable way to start a grudge.

Its three murders come from one episode, episode 7, in a stretch from April 2007 to August 2009. A single episode carries the whole count.