I'm glad you got the perpetrator. I always figured it was a coon, since that's their normal operating practice. You have to always be vigilant. I'd move the coop a little further from the trees too. Wild animals don't like to cross open areas, without any cover. A friend of mine worked at a federal corrections institution, and I told him I had a FCI too. He looked at me bewildered, then I explained to him it was a federal chicken institution. I think I've explained it before, but my chickens are located in an open area, which is surrounded by a solar electric fence. It's a pain to keep vegetation cleared from the lowest wire, but that wire probably does most work of the entire system. The chickens are further enclosed by a heavy duty farm fence. I also have Night Guard solar powered predator lights installed too. And there's a Great Pyrenees guard dog that's around nearby.
These precautions have developed over the years, and we've still lost one rooster and one goose to coyotes. However, the rooster was free ranging outside the fence, and he refused to stay within the enclosure, so he became a coyote snack. The goose was killed before the second, inner fence was installed. The big thing is to be vigilant, and realize that the entire animal kingdom loves chicken snacks. Down south, aerial predators are a big problem, and escape shelter need to be constructed to give the chickens a place to hide when hawks are looking for their next meal.
You might want to keep your pretty four legged friend out with the chickens occasionally. Her scent might be enough to warn off other predators. Oh, if the chicks were a little older, you could have fed the raccoon to the chickens, after it was dispatched. They would enjoy the extra protein. My girls had a special snack of some snake this week, all they left was the outer skin.
