The periods in the history of policing have seen significant changes in terms of professionalism, corruption, police brutality and violations of civil rights. This is not to suggest that these eras were identified by their problems rather to suggest that changes in policing strategies and tactics in previous eras were the deciding factors for change. There are some changes, such as education levels of police officers that were an attempt to professionalize the delivery of police services and not the result of some scandal or bad behaviors. At the same time the active courts of the 1960s and 1970s were not the result of bad behaviors either - just clarification of the rules for police conduct. You may want to examine the various commission reports on policing that may have impacted those eras and the attendant changes.
Question:
Why is the history of policing important to study?