Why is the Pottstown, Pennsylvania area so murdery, by murders?

Pottstown is in Montgomery County, eastern Pennsylvania, about an hour west of Philadelphia. Iron and steel built it. An ironmaster family set up a forge by the creek and founded the town in 1761, and it still holds the oldest mill in the country. Population now is 23,282. Rank 72 overall makes it third in Pennsylvania, which for a town this size is a lot of murders per head.

The Pottstown area covers two towns: Pottstown itself and Weisenberg Township, 25 miles out in Lehigh County, a scatter of small communities beyond Allentown where household income runs well above the national median and crime runs below average. Both sit in eastern Pennsylvania's belt of old towns and farmland an hour or so from Philadelphia, ground the show keeps coming back to.

The six murders come in two episodes and three dates: 1982, 1991 and 1996. Four of them are one 1991 case in Weisenberg Township, two thirds of the total. The Pottstown episode has two victims across fourteen years.