Getting in on this a bit late, but I'll add my two (confusing) cents. First of all, hawks do sit on spruce trees. Our chicken coop is built under a tall spruce, and a red-tailed hawk used to sit on the branches directly above the run and frighten my hens - after I put bird netting over the entire run because we lost a few hens to hawks. I think the hawk enjoyed this, and once in a while it would dive into the netting and really freak out the hens. Last year when free ranging and standing near the hens, a hawk dove at a hen that was just a few feet from me. Some black chicken feathers went flying, but the hen was ok. Every time we've lost a hen to a hawk, there were a lot of feathers scattered all around as the hawk, who couldn't pick up a hen, would pluck and eat the chicken right in front of her flock mates. For that reason, I wouldn't think it's a hawk. However, your chicken carcass does sound like it was so picked clean in places I can't imagine a mammal doing that. We also lost chickens to a clever raccoon in the daytime. Every day the raccoon came earlier and earlier until we finally shot it. But weasel - well, I've not lost any to weasels (thank God), but had an acquaintance lose over 50 pullets in one night to one. Just bit their necks and went on to kill the next and the next and the next...
I'm curious what your camera will show, but I do suspect a raptor.
We now have a bunker instead of a run - well, sort of. Fencing on all sides, above and below as well (so no raccoon or fox can dig under), plus bird netting to keep out anything that could squeeze through the fence - especially the sparrows who thought the chicken feed was an all-you-can-eat buffet, so they called all their friends and chowed down near the big birds.
I'm curious what your camera will show, but I do suspect a raptor.
We now have a bunker instead of a run - well, sort of. Fencing on all sides, above and below as well (so no raccoon or fox can dig under), plus bird netting to keep out anything that could squeeze through the fence - especially the sparrows who thought the chicken feed was an all-you-can-eat buffet, so they called all their friends and chowed down near the big birds.