S4·E16 Brother's Keeper

When Lorraina Garvey is found stabbed to death, the only clue Chris and Rita have is a call placed to the station reporting a red corvette leaving the murder site just about the time of the murder. At the crime scene, Rita finds an appointment book with the name Michael written in it many times. Upon talking to Lorraina's personal assistant, Rita discovers that the man in the book is Michael Ferraro--one of her old foster brothers. When Rita talks to Michael, he gives her a bogus alibi; and as he leaves, Rita notices that he owns a red corvette. While Donovan and everyone else just want to convict Michael, Rita believes that he is really innocent, and wants to help him. Meanwhile, Chris must nurse his aching back back to health after he his fall from a ladder while helping Rita paint her house.