These days most contemporary government documents are online, and increasingly many historical ones are as well. In addition to searching library catalogs such as the WSU Libraries' Search It catalog, and specific government databases (i.e. govinfo), you may find it of use to use Google's Advanced Serach capabilities.
Here are some examples (these work in Google, Bing, etc.)
Federal government
site:.gov predictive policing (you can put predictive policing in quotation marks to make it more exact)
site:.gov "predictive policing" filetype:.pdf
State government
site:.wa.gov "use of force"
The same is true for nonprofits and research institutes - these often have a .org extension, so... (remember that advocacy organizations and even research institutions can have a specific perspective, or publish multiple perspectives that must be acknowledged)
site:.org "predictive policing" filetype:.pdf
Be sure to look for links and tabs that lead to Publications and/or Research from the think tank or research institute. This is a great way to find "gray literature" - valuable research that can be hard to find using other sources. Also, note that these types of organizations can be governmental/public or private, and may sometimes have a particular political or other perspective that informs what they do.
Note: These may be scholarly, professional/practitioner, or both.