If you mean prisoners as in penitentiary inmates, I'd go with the crooked dice boiler suit types:

get the unarmed ones and some head sprues to .
There was a hostage set thet someone did, maybe RAFM or perhaps Ainsty or armorcast had them.....
It's Armorcast, in the tactical miniatures line:

Thinking about it, offensive have some hostages in with their terrorist set.

