I tried some searching in a few search engines and a few article databases and wasn't finding much about cops dissenting outright, or histories of police protesting their orders on a large scale, so I am not going to close this question in hopes that other librarians might be able to offer further help.

However, I have a few suggestions, since this topic might be one that may need to be approached in another way: instead of dissent or outright refusal of duties, you might look for instances of votes of no confidence in police administration (i.e. less direct acts of protest?).

Also, in recent news, there have been instances where cops took a stand: like in Arizona and Madison. There might be other historic incidents that you could research directly.

There may not be a complete history written (yet) about police dissent or internal, hidden viewpoints. I hope you can uncover one!