Hamas and Fatah are trading accusations over the gruesome murder of a 14-year-old boy whose decapitated body was found buried in the bedroom of a former Palestinian policeman in the Gaza Strip. The boy, Mahmoud al-Shaer, of Rafah, disappeared last week shortly after his father sent him to deposit several hundred dollars in a local bank. Over the weekend, Hamas's security forces arrested Rami Khalifeh, a prominent militiaman from Rafah who has long been involved in drug trafficking and smuggling weapons across the border with Egypt. Khalifeh's younger brother was also arrested as an accomplice. Hamas described Khalifeh as a...