In assaying fourth amendment jurisprudence, it is useful to take into account available knowledge regarding the actual search and seizure practices of the police. Especially helpful is the perspective afforded by the American Bar Foundation's Survey of the Administration of Criminal Justice in the United States, which ranks as the preeminent empirical study of law enforcement procedures in this country. Despite the fact - or, more likely, because of the fact that the ABF Survey was published over twenty years ago, certain insights from that study highlight some recent and significant changes in this corpus juris inconstans .
Clearly "the most important single finding of the Survey" was "how hard it is to make accurate straightforward statements about criminal law administration" because of the previously unperceived "complexity"· of that process. That complexity, the Survey established, attends activities of the police that implicate the fourth amendment. In deciding whether to make an arrest or other seizure of a person and whether to search for or seize property, the police are in actuality called upon to make decisions which are quite varied in their character and effect and which are influenced by a vast range of factors and considerations.
Wayne R. LaFave,
Controlling Discretion by Administrative Regulations: The Use, Misuse, and the Nonuse of Police Rules and Policies in Fourth Amendment Adjudication,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol89/iss3/3