Baretta comes to suspect that his close friend, a music store owner, may not only be a drug dealer, but may be unknowingly selling heroin so pure that it is killing his customers.

Baretta must use his wits to survive after he and a runaway girl he apprehended unwittingly get into a police car being driven by a couple of holdup men disguised as cops.

When a conventioneer is murdered, Baretta finds that the only witness is a busboy who doesn't want to get involved, but the real murderer is after the man too.

To find an arsonist, Baretta seeks the help of a former investigator who retired after suffering both physical and psychological damage in a fire.

While Baretta is investigating a series of waterfront killings, his cover becomes in danger of being blown by a waitress who knows him and thinks he is responsible for the death of her boyfriend.

Persuaded by his grandson to reopen the case of a retired cop supposedly killed in a fall, Baretta discovers a judge on the take.

To infiltrate a gang of jewel robbers, Baretta seeks the help of a former expert safecracker he once sent to prison.

When a dying hoodlum entrusts his girlfriend with a detailed record of all his underworld activities, she is sought by both the police and his former cronies seeking to protect themselves.

Baretta doggedly follows a truck driver he suspects of killing the cat burglar who injured his wife, waiting for the man to make a mistake that will reveal his guilt.

Baretta is investigating a mob theft of diamonds belonging to Mr. Nicholas and winds up helping a merchant who is threatened by a new group in the neighborhood called the East Side Benevolent Society, who is forcing all the shop owners to pay money for protection or suffer the consequences.

Baretta must find a nurse's 9-year-old sister, witness to the murder of a blind hot-dog vendor, before the killers do.

When his partner is charged with shooting a suspect in the back, Baretta tries to locate the only witness who can save the man's career, but the real murderers are after him too.

When a plea bargain falls through, Baretta must infiltrate a murderous motorcycle gang to save his informant.

Baretta tracks a distraught father who has killed the doctor he believes responsible for the death of his son, then has gone after the local drug dealers as well.

After a crime lord is arrested, Baretta must jeopardize an undercover policewoman to stop an escalating war of succession between gangland factions.

Believing that Baretta pocketed $500,000 in stolen bonds after stopping a robbery, a mobster takes Billy hostage until the money is turned over.

After a young pickpocket is killed, Baretta solicits the help of an expert to infiltrate the gang that operates at an airline terminal.

Baretta risks his life going undercover as a prison inmate to discover why two suspects in a jewelry heist were killed.

Pursuing a gunrunner with spinal meningitis, Baretta becomes infected and has 48 hours to find the man and his cohorts before he has to go into quarantine.

A retarded waitress who sees a narcotics cop commit murder allows herself to be persuaded that another man committed the crime.

When a mother has second thoughts after selling her baby, she helps Baretta infiltrate a group trafficking in black market babies.