Nope, but it should be.

Depends on local law. In some juridictions, any stray companion animal
is considered "pest" and can be exterminated according to certain
rules.  In other areas, you have to follow certain protocols before
taking any measures on your own.  It just depends on your local and
state laws.

-L.

That really sucks and I'd be suspicious of who exactly it was who took
your call.  Because these groups are all volunteers (some are paid,
but the ones answering phone calls normally aren't), it is sometimes
discouraging the kind of response you get.  If you're really concerned
about this and I think you are, can you try to escalate it and ask who
the groups Executive Director is and get in touch with them?  In my
area the SPCA isn't animal control but they certainly investigate
reports of cruelty.  Good luck.

Your ASPCA seems to have forgotten their purpose, and that's to eliminate
suffering in all animals. Anything less and they're just a warehouse for
strays. But then, you could have been talking to an untrained volunteer. Call
them back and ask to speak to the director. If you get the same response, ask
for the names of the Board of Directors that governs the shelter.
We don't have to have sworn statements here to start an abuse investigation. If
a caller chooses to remain anonymous, we still investigate. Depending on the
situation, we usually ask the county sheriff's department to accompany us; then
if the person is uncooperative, we come back with a search warrant. Like
another poster mentioned, best case scenario is that the suspect will be made
aware that there *is* a humane society where he can take the strays.
Truthfully, from what you've said, I don't think there's much chance for
prosectution unless you actually found a dead animal on his property for
necropsy, got sworn statements from neighbors, and found a trap there also.
It's just hard to make those things stick. Best hope is to scare the guy and
let him know he's being watched. I'm sorry. I wish they could put him away.