Scrawny Pete — Kristine Kathryn Rusch

Crime reporter Atkins discovered Scrawny Pete at the scene of a murder-suicide. The hard-bitten reporter took to the cat, and the cat took to him.
Together they travel through the city on the police beat -- until the day they come across another crime, one that Scrawny Pete understands.
“Kristine Kathryn Rusch's crime stories are exceptional, both in plot and in style.”
-- Mystery Scene Magazine