Kill it if you catch it.
Did it get them in a coop, or.....??
If so, tighten up your coop security.
Same family, yep...do other weasels have webbing too, or just mink?
Great catch, Congrats!...and great story, geez!
Regarding the smell, many animals have a musky odor similar to skunk.....and some animals eat skunks, found a skunk carcass near a fox den once.
Might want to block off access to under the coop if possible.