I didn't mean to imply that POWs were killed after the battle, and if you got that impression then I apologize. One thing that Olustee and Poison Spring and The Crater all have in common is that there is evidence that black soldiers were shot while wounded or while trying to surrender. Here is a
link to a dispatch from General Hatch concerning this.
Thanks. I'd seen your link -- it's where I got the information I mentioned above about Gen. Hatch.