Stone goes undercover as a bum to investigate the beating death of three homeless men.

Keller, temporarily partnered with a hotshot detective, sets out to discover why his new partner seems to be absolutely convinced of a murder suspect's guilt for no apparent reason.

In their attempt to bring down a family of con artists who victimize entire neighborhoods, Stone and Keller are aided by dissension among the gang members.

Stone and Keller suspect that an artist's fatal fall from his studio window was not an accident.

Stone discovers that a murdered woman was involved with both a famous newspaper reporter and his son.

After spending a "lousy" 12 years in prison for a brutal sexual assault and murder, a young punk returns to San Francisco to seek revenge against Mike Stone (who was the arresting officer). And he's not picky about how he'll take that revenge -- or on who.

A gang takes Mike Stone hostage after killing a policeman in an attempt to flee from a grocery store robbery. They want to trade Stone in for their leader, Buddy Sims.

A father finds out that the man who murdered his deaf son is released on a technicality.

A salesman attending a convention wrongly believes that he is responsible for the death of an attractive female hitchhiker who had lured him to her houseboat.

Stone appears to be the only one willing to give the benefit of the doubt to a convict who is accused of a murder while out of prison on a 36-hour pass.

A college professor, shot accidentally while trying to pay off a blackmailer, refuses to co-operate with Stone's investigation for fear that the publicity will lose him an upcoming promotion.

Two fishermen (Colasanto and Caruso) decide to keep quiet after witnessing a human smuggling ring.

A retired hit man returns to San Francisco, not knowing that he will be the target of a hit.

One witness in a racketeering trial is killed with a booby-trapped car, and Stone worries that the remaining witness, Roy Chaffee, will be picked off by a hit man if he surfaces.

When a boy disappears after school, suspicion falls on the neighborhood recluse, who is popularly known as a pedophile, although never convicted.

Stone and Keller face off against Gilliam, a wealthy executive who transforms women into his own special image of perfection, then kills them when they inevitably fail to live up to every demented standard of his.

After a female detective is killed by the rapist she had been bait for, her roommate (played by Brenda Vaccaro) goes on the warpath to catch him. After Mike Stone kicks her off the case, she continues on her own, hurtling headlong into peril.

A murder brings to light a coin dealer's plan to substitute fakes for the rare coins in a collection.

Mike Stone has reason to believe that the death of a politician is no accident.

A Vietnam veteran goes AWOL from the army in order to kidnap the son he has never seen.

When a corner newspaper vendor goes after the muggers who stole his life savings, Stone and Keller discover that the crime is linked to the murder of a housing commissioner.

The murders of a flight attendant and a nurse who were rooming together lead Stone and Keller to suspect a jewelry salesman and his wife.

A priest (Fr. Scarne) won't tell Stone where a murderer (Abel Hoffman) is hiding. Stakes are raised by drug smugglers looking for a stolen shipment of heroin.

Stone and Keller finally get a lead on a serial killer who has been knifing prostitutes when one of the victims survives the attack.

When a police officer is fatally shot 3 days before he is due to retire, Stone undertakes a relentless search for the killer.