Broken windows policing is a practice and theory that says that when low-level crimes are curtailed, it will have an impact on a larger scale. For example, the thinking is that a building with a broken window is more likely a target of more vandalism than a building without one. In practice, this way of policing creates a much stricter environment for residents and opens the door for racial biases.
Wikipedia
Broken Windows Theory
Video
The Impact of Broken Windows Policing on Black Communities
Molly Crabapple: How ‘broken windows’ policing harms people of color
Further Reading
How A Theory Of Crime And Policing Was Born, And Went Terribly Wrong (NPR)
The Problem with “Broken Windows” Policing (PBS)
The Dark Side of ‘Broken Windows’ Policing (New York Times)
Even the creator of ‘broken windows’ policing thought it could lead to racial problems (pri.com)
Broken Windows, Broken Lives: The Danger of the NYPD’s Quota-Driven System (Leitner Center)