https://www.amazon.com/Predict-Surveil-Discretion-Future-Pol...

Based on field work conducted with officers and IT personnel in the Los Angeles Police Department, the author convincingly shows that law enforcement generally follows an "institutional data imperative," i.e., a mandate to collect as much info as possible, in part by securing routine access to a wide range of data on everyday activities from non-police databases. Data originally collected for one purpose is used for another (p. 53).