I do think the Stocks should be forced to turn whatever animal this is over to wildlife experts. We could do tests on whatever it is and get to the bottom of it. I do understand where the Stocks are coming from though, and they're probably making money off it somehow.
If the animal the Stocks have is really a wild animal and not a dog, it's doubtful they have a legal right to be holding a wild animal. The cage/trap they have it in is extremely small and it doesn't appear it's able to maneuver around in it very much. At the very least, the animal needs to have tests done on it by experts, in order to determine what type of animal it is and if it's getting the right type of diet (they're feeding it cat food).
If you catch it you should be able to keep it, if it's on your property, and as long as you have the right stuff for said animal. If you plan to kill it and there are less than 100, you should probably give it back. People are under pressure if they are forced to do something.
the stocks have allegedly discovered the Chupacabra, but that doesn't mean they have an obligation to hand it over to wildlife scientists. While wildlife experts would likely identify the species and clear up confusion, that is an option that the capturing party should have. If they wish to get the Chupacabra stuffed and put on their wall, so be it.
I think that unless the animal is proven to be destroying property or injuring people then it should be allowed to be in the wild or domesticated by regular people, I don't think the Chupacabra poses enough of a threat that it is necessary to turn it over to wildlife experts.