Try these search terms in library databases:
"law enforcement" AND reform
("law enforcement" OR police) AND reform
"organizational change" AND (police OR policing)
"criminal justice system" AND reform
police AND reform
police AND "civil rights"
Discrimination AND "law enforcement"
Reform AND "law enforcement"
Police AND "social work*"
"Police brutality" AND ethnicity
Police AND "community relations"
Police AND Complaints AND "United States"
Police AND "Minority and ethnic groups"
Police AND ("African Americans" OR Blacks)
"Nonviolent protest*" AND police
These databases offer overviews and summaries of the issues. Start with a broad topic like police or police reform. In these relatively small individual databases, use simpler searches.
ProQuest Central will search millions of articles from thousands of magazines, newspapers (New York Times, Wall Street Journal, etc.) and peer-reviewed journals.
Reference Librarian Sam Berry-Sullivan created these tutorials:
How do you know a "scholarly article" (also called peer-reviewed or academic articles) when you come across one?
Articles in different fields may differ slightly (a scholarly article comparing two works of literature will lack data, graphs, and discussions of methodology, while a paper on the study of a new medication SHOULD have all of those things), but ALL scholarly articles will have items 1-5, and 7-8 on this list, as well as a references page (or works cited, or bibliography; the name varies depending on the field)
These video databases offer documentaries, TED Talks and more, with citations.
The titles listed here (and many more) can be accessed by copy/pasting titles into the "Start Your Research Here" box above.