Columbo (season 1)

Ken Franklin (Jack Cassidy) is one-half of a mystery writing team, but partner Jim Ferris (Martin Milner) wants to go solo; but it would expose the fact that Ferris did all the actual writing, and would leave the high-living Franklin without his cash cow. However, there is an insurance policy. Franklin makes it look like Ferris was investigating gangsters, then tricks Ferris into taking a trip to Franklin's remote cabin two hours away. Franklin stops at a general store for some provisions. Lilly La Sanka (Barbara Colby), the owner, goes outside while Franklin is making a phone call to Ferris's wife (Rosemary Forsyth) to establish his alibi. La Sanka sees Ferris in the passenger seat of the car. At the cabin, Franklin convinces Ferris to call his wife and tell her he's working late at the office. In the middle of the call, Franklin shoots Ferris, then takes his body back north and dumps it on his lawn.

La Sanka tracks Franklin to Los Angeles when he is out on a date and loudly approaches him, making clear what she knows and forcing him to cancel his date. He ostensibly goes along, brings her the $15,000 she wants for her silence, feigning interest in her. The two have an intimate dinner in the back of her general store, then he bludgeons her and puts her body in a boat which he capsizes to make it appear like an accident.

Final clue/twist: After hearing that Ferris wrote down ideas for his mystery novels as small notes, Columbo searches his office and house and finds a note with the fake-phone-call alibi and confronts Franklin. Upon his arrest, Franklin makes a startling comment: the alibi idea was in fact his own, the only good one he ever had.

Jack Cassidy played the murderer in a total of three Columbo episodes (this one, episode 22 (Season 3), and episode 36 (Season 5)).

Carl Brimmer (Robert Culp), the very tough, hard-nosed head of a private detective agency, with unfortunate and fateful anger issues, is hired by Arthur Kennicut (Ray Milland), a powerful publishing magnate who suspects his wife, Lenore (Pat Crowley), of infidelity. Although Brimmer indeed finds evidence of her being unfaithful, instead of reporting so to his client, he attempts to blackmail Lenore into revealing secrets about her husband. She refuses and tells him she will expose his plot to her husband, at which point Brimmer accidentally kills her in a fit of rage. He dumps her body at a scrapyard and later joins the investigation into Lenore's death with Columbo. Brimmer secretly starts to divert suspicion away from himself and even offers Columbo a job.

Final clue/twist: Unknown to Brimmer, Columbo employs a trick he learned as a boy to identify the killer. He tells Brimmer that one of Lenore's contact lenses might be found at the crime scene or the car which the murderer used. When Brimmer searches for it in the trunk of his car, he is caught by Columbo, with Kennicut in tow.

Robert Culp played the murderer in a total of three Columbo episodes: this one, episode 12, and episode 21.

Notes: This episode won an Emmy for writing and is known for the "glasses effect" after Brimmer kills Lenore where both lenses of Brimmer's glasses show different images of him cleansing the scene of the crime.

Major General Martin Hollister (Eddie Albert), a retired Marine Corps war hero, learns he is being investigated for embezzling military funds, then shoots his skittish accomplice (John Kerr). The act is partially witnessed by Helen Stewart (Suzanne Pleshette), who was in a passing boat. She is wooed by Hollister into doubting her own story. Noted Canadian actress Kate Reid plays Helen's disbelieving mother, who is favorably impressed by the distinguished Hollister.

Art critic Dale Kingston (Ross Martin) murders his uncle and tries to frame his aunt (Kim Hunter), to obtain what is considered to be one of the most valuable art collections in the world. He also murders his accomplice and art student, Tracy.

Final clue/twist: When Kingston hides the paintings he stole from his uncle after the murder in his aunt's house to frame her, Columbo can prove that they were in Kingston's possession. Columbo accidentally touched the paintings when he visited Kingston earlier in the episode. So Columbo's fingerprints are on them. When Kingston immediately claims that Columbo touched the paintings when they weren't looking, Columbo takes his hands out of his pockets to show he was wearing gloves the whole time.

Beth Chadwick (Susan Clark) murders her domineering older brother, Bryce (Richard Anderson), after he attempts to break up her relationship with one of his executives, Peter Hamilton (played by Leslie Nielsen), a man he thinks is only interested in Beth for ulterior motives. His mailing a letter threatening to terminate Peter's employment if he didn't break things off with Beth causes her to reach the tipping point and to act to gain control of her own life and, it turns out, the family business (as there are no other siblings).

Complications in Beth's plan contribute to Columbo's suspicions. Beth had planned to claim the shooting was an accident. She removed his house key from his key chain thinking it would require him, late at night, to try to enter the house via her bedroom. However, Bryce had a spare key which he had hidden under a flowerpot thus entering the house without ado. She improvises as best she can but her story will ultimately be undermined as a result of this turn of events. Meanwhile, her true personality emerges, showing a very different side than that shown earlier, before the murder.

Final clue/twist: When Columbo re-reads the testimony of Peter Hamilton, who had driven to the house after receiving the letter Bryce mailed him, he noticed that Hamilton climbed over the gates and heard the gunshots before the alarm went off, not after, thus tripping her up. The irony is that Hamilton did love Beth and was going to have it out with Bryce, yet he proves to be her undoing. Columbo tells Beth that, although he doesn't like it, Hamilton will testify what he knows.

Roger Stanford (Roddy McDowall) is a chemist and photography buff whose uncle, David (James Gregory), has taken over a business that his parents built and his aunt (Ida Lupino) controls. David proposes selling the business to a conglomerate in return for a seat on the board of directors, then tries to blackmail Roger into resigning. Roger decides to murder his uncle with a box of exploding cigars. William Windom guest stars as the next-in-line Vice President whom Roger will have to remove before he can take over the company. Anne Francis plays David's secretary, who is involved with Roger.

Elliot Markham (Patrick O'Neal) is an architect with a vision for a city of the future, and a penchant for classical music. His latest project is being bankrolled by the young wife of Beau Williamson (Forrest Tucker), a wealthy industrialist who has been away on a lengthy overseas business trip. When Williamson returns and finds out how his money is being spent, he is furious, and intends to cut off the funds. Markham decides that the only way he can continue his work is to eliminate Williamson. Simply killing him, however, poses a problem, because his money reverts to a trust fund when he dies. Markham comes up with a clever plan to conceal the body and make it appear as if Beau has gone on another long foreign trip. With Pamela Austin and Janis Paige as the women, present and past, in Williamson's life.

Final clue/twist: Knowing that Markham is after something by taunting him to dig at a construction site, Columbo goes the extra mile and starts an expensive excavation searching for the body. Later that night, when Markham tries to get rid of the body in a large hole created by Columbo's excavation (assuming that no one will look there again), he is caught by the police. Columbo's suspicion of Markhan began after he checked Williamson's car and found the radio turned to a classical music station, something odd for the country-music-loving Williamson!