The Santa Clara District Attorney's office says 25-year-old Robert Ray Farmer entered his plea Tuesday. He faces more than 16 years in prison.
Prosecutors say Farmer abducted the cats from the quiet residential Cambrian Park neighborhood.
Investigators arrested him last year after they found him sleeping in a car where the carcass of an orange tabby cat and several cat collars were later discovered.
Authorities say Farmer may have killed up to 16 cats. Only four bodies were found.