Sorry to be the voice of dissention but... are they sure it was a person? It's common down here in unprotected aviaries for raccoons to grab a hold of birds and rip/chew their feet off through the bars

They get mad they can't get to the birds and will reach through the bars to grab them. I've also head of them ripping off wings, whatever they can get their grubby little hands on... I'm sure they can tell the difference looking at the wounds, but just food for thought.
People are sick. I'm honestly excited in moving to AZ - animal cruelty there is a
felony not just a misdemeanor. Guaranteed jail time, not just a slap on the wrist. They have a feral cat problem and if you're caught poisoning them or trapping them incorrectly, it's cruelty. Down here even when you report someone to AC&C they don't do crap. I know, we had AC&C called on our shop when the new owners took over it, multiple calls a day, and nothing happened even when we personally, as staff, showed them what the new owners were doing They just told people to stop calling because they were tired of responding and they would start fining people for calling

Wanna know why Michael Vick got away with it for so long? AC&C here sucks. If we find a lost dog in the neighborhood, even if it's aggressive, they won't come out and pick it up unless we have it contained. I laughed and said "ok, so you WANT me to go out, grab this dog, and tie it to a tree until you can get yourselves over here, even tho it's a 90 lb aggressive dog?" and they say yep, or we won't come out. So stupid!
We have a kid in our neighborhood we've named Jeffrey Dahmer. It's sad, but I feel no guilt. I've called him that since he was 3 and killed another kids guinea pig by throwing it at a wall because 'it was creepy'. He goes out snake hunting and then rides around on his bike carting them around, holding them by their tail and swinging them, etc. He regularly will beat up neighbor's dogs if he goes to their house and then will try to say the dog bit him. Caught him doing it ONCE with my schnauzer and, hate to admit, I whacked him in the back of the head when he kicked her for jumping on him - kicked her HARD. He was 10 so... minimal guilt on my part, I honestly things he needs some more smacks and needs his arrogance beaten out of him. His parents have NO sense of control or responsibility. He's a nut job and scares the crap out of almost everyone because he's so serious, so crass, and so emotionless. I'm not one to jump on the sociopath bandwagon, but this kid is it. He's 11 now and just moved... BIG sigh of relief for everyone lol!