I have bneen playing recently, Alien Vendette, on ultraviolence with faster monster/monster respanw enabled. [oh, don't worry, i have my repeating railgun

] and i noticed when i clear a room out, leave, come back, kill the respawned monster, the corpse number stays the same.
Do monster have unique ID's or something so that when a monster respawns it reuses the body or something of a previously slaine coprse?
If not, how can i make corpses and bullet holes stay forever?