Hey guys, I am in need of some help. I live in a city and have four chickens in my backyard, which is surrounded on three sides by a 6ft privacy fence and the other side is 4ft chain link (so completely inclosed). We let our chickens free range from time to time, more often lately because one of our hens was getting picked on and it seemed to help when they were occupied with pecking and scratching in the yard. The last few nights I left them out when we left for work at 4:30pm and locked the door when we got home around midnight, they were always roosting when we got home. My husband and I left for work at 4:30pm tonight like usual and got a call from my neighbor at 6:30pm saying one of our hens was in our front yard, which has never happened. We thought it was weird but just asked her to toss her back over the fence. She said she fought going back over and tried getting back out once she was in there. When we got home at 9:00pm we found three of our chickens dead spread around the backyard. They all have been bit in the neck and two had bites under the wing. One was still alive and looking at us but she was so far gone we had to put her out of her misery. None of them were eaten but one was drug from the coop to near our house. The hen that somehow got out of the backyard survived. So between 4:30pm and 6:00pm during daylight it happened. I have attached pictures showing their wounds. Like I said we live in town and have never had any issue in the past, though this is our first year raising chickens, they just began laying a month ago. We are heartbroken about it and would greatly appreciate any help identifying what could have done this. Thank you.