Did he deliberately kill her or by accident as force-breeding too much?
If he deliberately killed her, remove him ASAP! Just kick him out of the coop or whatever immediately. Rooster killing hens on purpose is very rare and is a sign of something really wrong with him.. which translated to most likely he will do it again.
If it was by breeding too much, then yes he will do it again. Those roosters pretty much have just one thing on their minds, they just don't care if they are hurting or killing the hens. Those will do better with more hens, only because it is less likely one or two hens will get "too much attention".
As you don't care about fertilized eggs, get rid of him right now anyways. Roosters are totally irrevelant if you do not intend to hatch or breed from the hens. Even if you want to hatch eggs, can just get fertile eggs from someone and tuck it under a broody hen..
Sorry on your loss.