Mass Grave sites

http://www.infowars.com/video-footage-of-phoenix-mass-grave-site/

What if these are already filled with bodies?
Why do they need these mass graves site?
And if they have not been used, who are they going to put in all these graves?

http://video.google.com/videosearch?q=phoenix+mass+graves&rls=com.microsoft:en-us:IE-SearchBox&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA&um=1&ie=UTF-8&sa=N&tab=wv&ei=SODLSeDVK5fWlQeYkaXjCQ&oi=property_suggestions&resnum=0&ct=property-revision&cd=1#q=my+reaction+to+the+mass+grave+sites+in+phoenix+&emb=0