In the series premiere episode, O'Hara tries to nail a rackets boss on charges of income tax evasion.
This time, O'Hara is out to bust up a gun smuggling operation.
O'Hara Investigates the counterfeiting and theft of U.S. Savings Bonds by a criminal syndicate.
O'Hara wonders if a crooked IRS agent is in league with the blackmail scheme of a small-time grifter.
O'Hara races against time to find and defuse a bomb.
O'Hara goes up against an aging Burleque queen who is now running a counterfeit money operation.
O'Hara goes undercover as a carnival worker in order to trail a shipment of heroin through Mexico.
The estranged wife of a gambler tips O'Hara that hubby might be a tax evader in league with organized crime.
O'Hara goes undercover as a truck driver in order to recover stolen explosives.
This time O'Hara pulls undercover duty as an air cargo handler in order to solve mysterious thefts of valuable imported objects.
O'Hara goes to a small town in search of income tax violations.
O'Hara tries to set up a crime boss by convincing him that he's on the take.
O'Hara seeks the source of moonshine that has been contaminated by lead
O'Hara poses as an arms dealer to find the source of new machine guns that are ending up in the hands of criminals.
A compulsive gambler keeps getting in O'Hara's way when our hero attempts to smash a ring of counterfeiters.
O'Hara goes after a smuggler suspected of committing three murders.
O'Hara gets an uneasy feeling when he accompanies a diamond broker to Africa to investigate a diamond smuggling ring.
O'Hara must build an income tax evasion case against a con man who specializes in art swindles.
O'Hara must find a missing counterfeiter before vengeful racketeers do.
The bitter wife of a mobster sets hubby up for a fall but at the same time she endangers O'Hara.
O'Hara goes undercover as a dealer in a casino to prove that its owner is hiding cash from the IRS.