The police has always been a tool of repression

Sam Mitrani explains how the police from the start was created to control the working classes:

There was a never a time when the big city police neutrally enforced “the law,” or came anywhere close to that ideal (for that matter, the law itself has never been neutral). In the North, they mostly arrested people for the vaguely defined “crimes” of disorderly conduct and vagrancy throughout the nineteenth century. This meant that the police could arrest anyone they saw as a threat to “order.” In the post-bellum South, they enforced white supremacy and largely arrested black people on trumped-up charges in order to feed them into convict labor systems.