The Oregon Humane Society has offered a reward of $1,000 for help in catching whoever has has been leaving the bodies of dead animals on the campus of Portland State University over the past month, reported the Portland Oregonian Monday.

Veterinary doctors say the wounds on the cats, including four kittens found outside the library, indicate both blunt force trauma causing death and also mutilation or torture.

"We're concerned. We know -- it's been proven -- there's a link between abuse or neglect of animals -- or violence toward animals -- and violence toward people," said veterinarian Kris Otteman to the Oregonian.

Portland State University campus safety officers and humane society staff said they're hoping a tip will help find those responsible for the violence.