Is it possible to search for photos in a Lightroom-5 catalog that aren't geotagged?
Enable Filters (in the Library menu), select the Metadata filter, then choose the "GPS Data" filter. There, you can select "No coordinates." Of course, if there are no coordinates, it's not geotagged. Similarly, you can use any of the location filters ("Location," "City," "State/Province," and "Country") and choose "Unknown..." to filter for those with no information.