I'm pretty sure this just happened to us... 2 silkie roo's which are the youngest of 13 additional hens... My best egg layer was dead this morning... I've seen one of the roosters go after one of my hens, but thought it was a mating thing... I don't want another one dead. They will be outdoor roos and I will supervise when all are free ranging for now...these are my first roos so live and learn I guess..I see why people don't keep them... Unfortunate..
In all my years of chicken keeping, I've never had a rooster kill a hen. Never. If it happened during the night, I am confident in saying it was not your rooster. What kind of marks did she have on her?