State police jurisdiction in the United States
"At the outset of this study of the present jurisdiction of each of the state police organizations of the Unites States, it will be worthwhile to consider some of the factors which brought the state trooper into the state law enforcement picture. It is also necessary to review briefly the past and present duties of the sheriff. In doing this, it must be remembered that a complete analysis of the authority of the sheriff is beyond the scope of this study, for the intention is to suggest that the present day sheriff, because of the numerous duties imposed on him, could not hope to solve today's law enforcement problem. Since the state police often exercise authority similar to that of the sheriff, the duties of the sheriff as a peace officer require a brief survey." --Introduction.