Cat in the Dark by Shirley Rousseau Murphy

"Of course I worry.
What if the cops witness a cat opening a skylight and
masterminding a robbery?
The tabloids will love it."

There's a new pair of thieves in MolenaPoint, California, a renegade yellow-eyedtomcat with a cold disdain for the law,and a scruffy human partner who isno better. The two, clever and silentat their work, are bad news indeedto crime-solving cats Joe Grey andDulcie. But when Joe learns the pair'sconnection to a good friend, and then an innocent couple turns up dead in the library garden, Joe and Dulcie must engage in some fancy paw work to unmask the deceptions and route the real killer -- before his brazen criminal crime spree careens madly toward them.