Many criminals made the mistake of underestimating Lieutenant Columbo, a homicide investigator with a crumpled trench-coat and a beat-up car, who certainly acted as an incompetent bumbler.
But he was so polite to every suspect, and he talked so much about his wife (who we never got to see on any episode, but who many believe later had her own show, starring Kate Mulgrew, later of Star Trek: Voyager fame) that he lulled even the shrewdest murderer into a false sense of security.
And although the audience had witnessed the murder in the beginning of each episode, it was still a surprise to see what mistakes the killers had made during the seemingly perfect murder.
Columbo's first mystery pits him against a cheating doctor out to get rid of his wife in favor of his young, pretty actress girlfriend.
A high-flying lady lawyer kills her husband for the insurance money, and tries to makes It look like a kidnapping gone wrong.
One member of a mystery-writing-team decides to kill his more talented partner when the better writer decides to go solo.
A private investigator kills his client's wife after she threatens to expose his blackmail scheme. The client then hires the detective to assist Columbo in the search for the killer.
A famous general kills a business associate, then woos a neurotic female witness to thwart Columbo's investigation.
An art critic, Dale Kingston, kills his uncle for his valuable collection of paintings. All the clues lead to the dead man's first wife. Can Columbo correct the Lieutenant's error before it is too late?
A woman shoots her overbearing brother, claiming she thought he was a burglar. Columbo doesn't buy the self-defense claim - he know's it's murder
A chemist rigs a bomb in his uncle's car to gain control of his uncle's company, then plants clues to make Columbo suspicious of the company's Vice-President.
An architect kills his business partner and deliberately lets Columbo suspect him, leading Columbo to think that he's hidden the body in the foundation of a building under construction. He plans to let Columbo dig up the site and find nothing, knowing that its the perfect place to hide the body since Columbo would never look in the same place twice.