Grants sometimes require you provide justification for funding, and research in scholarly journals and statistics are a great way to support your application.
One great way to find grants online is to limit by specific types of websites in a traditional Google search. For example, you can search all .gov websites by performing a site search.
site:.gov police and grants and Florida
You can also add additional keywords for programs or equipment:
site:.gov police and grants and body armor
You can also use the same structure to find information on .edu, or .org sites, but make sure you evaluate each cite before you use it.