Recently, Dita Oepriarto's residence in the Wisma Indah Complex, Surabaya, East Java, began to receive routine visits by the same group every Sunday: Anton Ferdianto and his family from Wonocolo, Sidoarjo, a city close to Surabaya.

Anton, 47, would always bring his wife Sari Puspitarini, whom he married 19 years ago, and his three children, HA (17), AR (15), and FP (11). “We would get there after sundown,” AR told the police last Tues