Wikisimpsons - The Simpsons Wiki
Murder Town is a neighborhood of Springfield.
Little is known about Murder Town, but judging by its name, it has a reputation for violence (murder in particular). When Springfield installed a network of CCTV cameras, Murder Town was one of the many locations included in the surveillance.
Ned Flanders was one of the people monitoring the video feed. He was watching Murder Town and was puzzled by the utter lack of anything happening on the monitors. It turned out that all of the townspeople were in the back yard of the Simpson home, where Bart had discovered a gap in the video coverage.