I've looked all over the place for a "POLICE, DROP YOUR WEAPON" wav or "FREEZE, POLICE!"... anybody know where something like this might be hiding?

Ok it's totally slim pickin's out there, there's maybe 1 wav per site that will work for you, at least it might get you started:

http://www.gryeyes.com/sounds.htm
http://www.a1freesoundeffects.com/radio.html
http://www.wavsource.com/sfx/sfx2.htm
http://frogstar.com/wav/effects.asp
http://silence.imon.org/lambs/senses.html
http://www.moviesounds.com/robocop.html
http://www.waveevents.com/nuke/errorwavs.php
http://new.wavlist.com/movies/290/