I am so sorry for your lost I know what it feels like, for I have lost my chickens to many predators: dog, raccoon, hawks, and I not quite sure if it was a mink or some kind of weasle. We have caught raccoons and a mink/weasle in a live trap. But I do know that we had raccoons outside of our coop at one time and lost alot of chickens all at once. So we think maybe a family of coons. I hope you catch the predator. But you might want to invest in a live trap if it is a coon then you can make sure it gets taken care of.