Back when policing forces were new, and still finding their identity

Explanation:

https://en.wikipedia.org/wiki/Battle_of_Liberty_Place

While the notion that policing forces in the US grew out of slave patrols is widespread, it is not strictly speaking true - in the 1850s, many locales simply did not have formal policing forces, which was still a cutting-edge innovation from Britain (see: Peele’s Principles ). In the post-Civil War era, Federal Reconstruction in the South led to an increasing need for abstract law enforcement which did not rely on mob consensus.

Sadly, the reversal of Reconstruction resulted in many of those newly-established law enforcement organizations in the South being taken over or subverted by the enduring racist majority; while in the North they took the more ‘usual’ route of being subverted by monied interests in politics. Later, US policing would become more insular and a political power in and of itself, which was… not really any better.