VANCOUVER, Wash. - Someone hanged a puppy from a tree in Vancouver, killing the 4-month-old pit bull, and now police are trying to identify the killer.

Owner Totiana Hayes found the puppy - named Hercules - suspended from the tree in her backyard on East 18th Street two weeks ago.

She had left the puppy and its dad, Zeus, tied up outside in the yard while she was gone, something she said she rarely does.

Someone snuck in and hanged the dog, and the next day she found a letter in her mailbox addressed to her dogs. It said the dogs' owners should take better care of the dogs and that they cry all night and were going to be reported.

It was unclear Thursday if that letter was connected to the puppy's death. Police were dusting it for fingerprints and interviewing neighbors.

"I don't know what kind of person it was that did this or even why because there's not enough whining an animal could do in this world for me to even pass the thought of killing an animal," she said.

Hayes believes someone killed Hercules simply because he was a pit bull. And had Zeus not been so big, she believes he may have been killed as well.