Example:  Search for "police search apartment garbage."  This is a brute force sort of search designed to show you the breadth of filterig options available to you. If you have a unique word (e.g., "curtilage,") this sort of search will bring up all occurrences.  If you have a concept that may be described in a number of different ways, this sort of search will give you a lot of options to review, to help you refine your search. 

Both Lexis and Westlaw work in generally the same way:

1)  Run your search

2) Choose your source type first  (cases, legislation, secondary sources etc.)

3)  Once you've chosen your source, then use the filters along the left-hand side to reduce the result set.  Clicking on "9th Circuit," for instance, will show you only those results that come from the 9th Circuit.  In Westlaw, you must click the "apply filters" button at the bottom of the left-hand column in order to get the new results. 

4) Continue to filter, or start over with a more precise search. 

Check out the timeline for an overall sense of the discussion of the topic over the years, but take care not to unnecessarily restrict results only to relatively recent cases.