Police/Law Enforcement

What are the central issues facing contemporary policing/ law enforcement?  Is there a reasonable “theory” of policing?  What is the value of a college education in policing?  What do the fields of psychology, economics,
anthropology, sociology, political science, popular culture, ethics, or geography have  to do with policing?  Under what “context” do/should we study policing?  Which direction should we focus our attention: corruption, selection/recruitment,  community relations, use of excessive force, etc.?  What purpose do they serve?
What is the function/ role we wish our police officers provided?  What do issues such  as justice, ethics/morality, discretion, or types of police service have to do with what  happens in contemporary policing?  What is/are the theory/ies of policing?