Answer:
watch system or neighborhood watch
Explanation:
Based on the information provided within the question it can be said that the system of policing that is being described is known as a watch system or neighborhood watch. Like mentioned in the question this refers to an organized group of citizens that patrol the neighborhood during the night in pairs. This is done in order to prevent any unlawful behavior during the night and allow other individuals to sleep with peace of mind that the neighborhood is safe.
