Please help identify our predator!

Earlier this week we had our 3+ month white leghorn attacked in our coop. We thought it happened outside the coop but after last night have changed our mind. Anyway, her wing had a great many feathers torn out and it was a bloody mess. I started putting ointment on it 3 times a day and separated her from the flock by putting her in our 6' fenced in garden. 2 days later she was gone without a trace. No feathers or anything (there were a lot of feathers after her first attack). We figured an owl took her away that night but still wasn't sure about her first attack. Last night, something got into the coop and removed our other pullet (the rest of the girls are full grown). and left a lot of feathers an only a small bone. Nothing else. Everything I read says coons and possums just take parts of a chicken and leave remains. The run is also 6' but there is a small hole under the gate although whatever it is may have gone over. There are also plenty of trees. The coop itself is pretty sturdy but we hadn't locked the roof and it raises up. We're guessing something crawled into the coop and pulled this girl out and dragged her off. There was a bunch of feathers on the ground near the coop but like I said, nothing else. What could it have been? I know a coon could open the roof, but could a possum...and would they leave no calling cards? There is also a ferral cat we have chased off (we also have a 4' picket fence around our yard). Could he have done this? Could he have gotten into the coop? What else could it have been? The ground is too hard to show any tracks The coop is a 2 story tractor and the roosting area is on the 2nd story. I've had chickens about 2 years and have lost 3 this year alone. One to a hawk (our favorite layer) and now 2 young ones to something else. And it couldn't have been a worse week. My son broke his arm and ended up in the hospital for 2 nights after surgery. I can't take much more!

 

Okay...I finally went out with my husband and we did some forensic work. I found a foot and farther away I found some entrails and then found a hole where they pushed up the fence to get out. There was a heart or something outside the fence. It looks like he climbed over the gate on one side of the run (which doesn't have a hole under it after all). He then climbed up on the handles and ripped open part of the roof. I found long variegated fur on the inside of the roof. He must have grabbed her out and drug her to the other side of the coop where he started his feast then drug more of her toward the fence on the woods side. Not sure where the rest of her is. I found more of our leghorn feathers out there too. But, no place around the garden for him to get her so it must have been from the original attack. Or from the owl. We also found some mammal scat with white fur in it. Not as messy as fox scat so we originally thought it was the feral cat but after seeing the coop damage we're pretty positive it's a coon. My husband is trying to reinforce the roof right now and I plan on getting a trap. Not sure what else to do. Not much more we can do with this coop design. I'm afraid the coon will rip the roofing material off. It's the clear roofing corrugated roofing stuff. We can latch it down but how strong is a coon? Also, where should I place the trap to entice him? On the side where he's been getting at the girls? Will he try the other side of the coop/tractor? It's out under the tree canopy to keep them cool and hidden since we're in a subdivision.