Wiktionary
n. (context criminology English) A criminological theory stating that signs of urban decay (e.g. broken windows, graffiti) signal that an area is not monitored, encouraging more destructive criminal behavior.
Wikipedia
The broken windows theory is a criminological theory of the norm-setting and signaling effect of urban disorder and vandalism on additional crime and anti-social behavior. The theory states that maintaining and monitoring urban environments to prevent small crimes such as vandalism, public drinking, and toll-jumping helps to create an atmosphere of order and lawfulness, thereby preventing more serious crimes from happening.
The theory was introduced in a 1982 article by social scientists James Q. Wilson and George L. Kelling. Since then it has been subject to great debate both within the social sciences and the public sphere. The theory has been used as a motivation for several reforms in criminal policy, including the controversial mass use of " stop, question, and frisk" by the New York City Police Department.