Usually a Weasle will kill everything it can get ahold of, they kill for sport. I would suspect a skunk or opossum as they are interested in the eggs. A live trap is your best bet, baited with canned cat food or a cracked boiled egg. You will need a small tarp or blanket in case you catch a skunk. (I work at a Zoo and we catch them all the time) Believe it or not as long as you are calm and stay quiet they will not spray when you approach. Just walk up and lay the tarp over the trap then you can pick it up and carry it. Call animal control if you live in town or if not you will need to shoot the animal while it is in the trap. Do not transoprt it somewhere else to release it. In most areas it is illegal to transport wild animals across county lines and anything closer and the animal will just find it's way back as they are territorial.
I am sorry for your loss, hugs to your kiddo.
I am sorry for your loss, hugs to your kiddo.