I believe him. Cats are sneaky, and a Sears employee would never do such a thing.
From The Smoking Gun.

SEPTEMBER 10--A Florida man who told police that his cat somehow downloaded child pornography onto his computer was sentenced this week to more than 12 years in prison.
Keith Griffin, 49, pleaded no contest to 25 felony counts stemming from a probe launched last year by the Martin County Sheriff’s Office. The Jensen Beach man, who worked as a Sears
salesman, was targeted after investigators determined he was using a file sharing site to distribute child pornography.
When agents last July raided Griffin’s home (which he shared with his teenage son) he “stated he has accidentally seen child pornography while using Limewire,” but that he would “usually delete” those files, according to a sheriff’s report.
Griffin, investigators noted, added that, “sometimes he would leave the computer on and his cat would jump on the keyboard and he would come back to the computer and find strange things on his computer.” He did not further describe how his talented cat succeeded in downloading these “strange things,” or what he did with these files.
Griffin, pictured in the above mug shot, will be imprisoned until early-2022. The cat, who has not been named, was not charged.
(Full story at The Smoking Gun)