What killed my chickies?

Tonight after everyone was inside, we did our routine head count only to come up two short. One was welsummer roo . The other was a pullet hatched by our first broody. My whole family went out to look and the good old dog found em first. the roo was just 20 ft. away from the coop right on the edge of the woods, his head, neck, and breast meat was gone. the pullet was about 50 ft. deep in the woods with just her head and neck missing. So what did this? I planned on getting rid of the welly roo in the spring, but that pullet was a real sweetie, and a beautiful little mix, BO/Speckled sussex.
They were both 3-4 mo. Here in VA, snow is absolutely coming down and neither was covered so it probably happened around 6:00 ish. This is our first real loss to predators. I'm thinking it was the same bugger, he got one ate it, then got another. It was big enough to drag the pullet pretty deep into the woods. Is it a coon or maybe a possum? we have seen tracks around.
thanks

 

I don't think our dog would hurt the chickens. We leave him outside all day with them, and for the most part he completely ignores him. He's interested when i get new ones, but ignores them after a few days. That leaves a fox or coon I guess. I've seen small prints (about the size of a quarter or half dollar) with longs claws all around our creek which is just a couple hundred feet away. I'm going to be more careful about letting them out now, although I don't think they'll be out in awhile. So far we've got like a foot a snow, and it's supposed to keep going all through the night.