John Ricca is a character in the Monk series.
He wrote a book called Paper Cobra, which was about the deceased Sonny Chow.
One night while watching an interview about himself involving his book, a man breaks into his apartment with nunchucks and attacks him. John tries to get away, but is killed by the man.
When the police arrive, they find that John appears to have gotten some hair off of his attacker, which can be used for DNA. It is also seen that 'CHOW' is written apparently by John in his own blood. It appears that Sonny Chow isn't dead, and has killed John Ricca because of the highly critical book Paper Cobra, which made Sonny look bad. When the police test the hair to see if it matches Sonny Chow, the test comes back positive.
Actually, the attacker wasn't Sonny Chow, and Chow has always been dead. The attacker was Chris Downey. Chris had hid jewels (that he stole) in Sonny Chow's 'death pillow' in his coffin, which was right before Sonny was buried. Chris was arrested for another crime however, and spent six years in jail (since the police never found the jewels, they couldn't charge him for stealing them). When he got out, all he had to do was dig up Sonny's coffin and re-steal the jewels. However, a massive monument was put over Sonny's grave, and Chris couldn't get it moved by himself.
Chris attacked John Ricca, placing hair from Sonny (that he stole from a hairbrush that belonged to Sonny) at the crime scene and also made it appear John had written 'CHOW' in blood. The police had to see if Sonny Chow was really dead, and thus moved the monument and dug up his body. With the coffin now out, Chris could easily take back the jewels.