Oliver on Maine's Role in Shaping Modern Criminal Procedure

Portland, Prohibition, and Probable Cause: Maine's Role in Shaping Modern Criminal Procedure is a new paper by Wes Oliver, Widener University School of Law. Here's the abstract:

At the time the Constitution was written, police officers had very little power. In most cases they were required to wait for a complaint from a victim to arrest, or a warrant from a magistrate to perform a search of any kind. Victims had extraordinary discretion in this era. Generally, only victims could seek arrest or search warrants and they were required only to allege that they had probable cause to support the arrest or search they sought. In most cases, an officer could not obtain a warrant even if he could provide the facts supporting his suspicions. Warrantless arrests exposed the officer to a very real threat of civil liability. Officers' arrest powers were substantially increased in the mid-nineteenth century as they were granted immunity from civil liability for arrests made in public, so long as the arrest was supported by probable cause. This new standard accompanied the creation of professional police forces, but in many states was immediately preceded by another legal development - prohibition. A new search standard was needed to enforce prohibition as this new crime had no victims. The new standard permitted anyone to obtain a warrant to search for alcohol, but the affiant had to provide the magistrate with the factual support for his belief. Probable cause thus went from a pleading requirement that victims alleged to a factual threshold that an affiant could satisfy. Very soon thereafter courts would accept this new probable cause standard as the basis for police arrests. Maine was source of the this first prohibitory law - a law that was copied by the majority of American states in the mid-nineteenth century. This article traces how the search and seizure of Maine's early liquor laws were created and how they influenced the development of modern police powers throughout the nation.