Has all the markings of a fox to me. Foxes will go on a killing spree and kill several chickens then make trips back and forth to its den retrieving the dead chickens.
Been doing this for a while and have lost whole flocks to foxes before getting my infrastructure setup correctly. Red foxes are the worst as they are several times smarter than just about any predator you will have to deal with.
If it was a fox and you don't protect your chickens, he will be back.
Bottom Line is you have to protect your chickens. No free range pasture grazing without protection or supervision. They have to be secured in the coop at night.
Protecting the chicken can take several routes. If you go with fencing with has to serve two purposes.
1. It has to keep the chickens in. That means it has to be high enough to keep them from flying out or, you have to clip their wings.
2. It has to keep the fox out. About the only way I have found effective is a very strong set of electric lines. I'm talking at least 8000 volts. It has to be on the outside of the fence so the chickens cant easily get into it.
I have two flocks right now. One set is in a fenced in area like the one above. The other is in a rather large totally enclosed runner with attached coops.
I let all the chickens out in the evening for a few hours supervised so they can graze.
All this said. If its a raccoon, you can trap it with a live cage. I have caught several with just peanut butter. I have only caught one fox though and I had to use one of the dead chickens he left on a killing spree. If I catch a coon, I keep them in the cage (with water) all day inside the back of a trailer that I pull behind my tractor as I do chores. In the evening I let it go. Believe me, he thinks twice about coming into the area. I hate killing animals, and besides if you kill all the small game, you will have the coyotes to deal with when they get hungry.
Foxes on the other hand have to go. They will come back.
Another option is to get a guard dog.
