Honestly, I'd just buy in bulk the legs, torsos, and caps, then I would pick out a bunch of random heads and put them together.
If you want to get some accurate policemen, here are the links:
Torsos:https://www.bricklink.com/v2/catalog/catalogitem.page?P=973pb0261c01#T=S&C=11&O={"color":11,"st":"4","iconly":0}
Legs:https://www.bricklink.com/v2/catalog/catalogitem.page?P=970c00&idColor=2#T=S&C=2&O={"color":2,"st":"4","iconly":0}
Caps:https://www.bricklink.com/v2/catalog/catalogitem.page?P=3624&idColor=1#T=S&C=11&O={"color":"11","iconly":0}
Caps are optional, you could always add hair. And then pick any head you want, whether it is yellow or flesh toned.