The series is noted by TV critics and historians for the way it reversed the cliché of the standard whodunit mystery. TV Guide referred to the basic plot structure as a "howcatchem", although it is more properly known as an inverted detective story. In a typical murder mystery, the identity of the murderer is not revealed until the climax of the story, and the hero uncovers clues pointing to the killer. In almost all the episodes of Columbo, by contrast, the audience sees the crime unfold at the beginning and knows exactly who did it and how it was done; the "mystery", from the audience's perspective, is spotting the clues that will lead Columbo to discover the killer and the tricks used to obtain a confession in the absence of other non-circumstantial proof. This allows the story to unfold simultaneously from the point of view of Columbo and the murderer, as they play cat and mouse, rather than solely from that of the detective.
In some episodes, such as the first pilot, "Prescription: Murder", Columbo does not appear until as late as 30 minutes into the story, the preceding time being taken up depicting the complex nature of the crime, including the history of the killer-victim relationship and the effort by the killer to conceal his guilt. A Columbo mystery therefore tends to be driven by the characters and by the gathering of subtly damning proof in the field, rather than by forensic science labs, whose personnel are largely unseen and their findings merely announced in passing or by general canvasses or rigorous squad room interviews, as portrayed in programs like Homicide: Life on the Street or NYPD Blue.
The audience observes the criminal's reaction to the ongoing investigation, and to the increasingly intrusive presence of Columbo, whose personality and manners are initially disarming and non-intimidating. Columbo is unfailingly polite to a suspect as an investigation proceeds. Class tension is often apparent between Columbo — with his working class origins — and the killer — who is usually affluent, well-positioned or naturally condescending. The killer often "helps" Columbo with his investigation, with his/her level of irritation, arrogance or panic escalating as the noose tightens and Columbo gets closer to exposing the killer, discovering too late that the Lieutenant is not nearly as simple-minded as he appears. When the final arrest comes, the killer always goes quietly after revealing both his/her guilt and his/her motives. Columbo often manipulates the killer(s) into self-incrimination. This predictability and the quirky mannerisms of Columbo – partly his natural personality, partly an affectation to give him an edge in his investigations – are part of the attraction of the series. In some instances (such as Ruth Gordon's avenging mystery writer in "Try and Catch Me", Janet Leigh's terminally ill diva in "Forgotten Lady", Donald Pleasence's vintner in "Any Old Port in a Storm", or even Vera Miles' besieged industrialist in "Lovely But Lethal"), the killer is more sympathetic than the victim or victims.
Columbo rarely displays anger toward the (usually well-to-do) suspects, though he sometimes does at non-suspect witnesses, and in an impromptu speech to a ladies' club meeting hosted by Ruth Gordon's character, at which he shows up uninvited, he admits that over the course of many of his investigations he grew to like and respect the suspect. Among the few instances of his expressions of genuine anger with a suspect were in the episodes, "An Exercise in Fatality" and "A Stitch in Crime". In the latter, when Columbo's investigative techniques initially appear to prove futile against a heart surgeon (Leonard Nimoy) he thinks is a murderer, Columbo drops the facade, reveals his cards, and angrily promises that if the patient dies, the body would be autopsied to collect the evidence required to put the doctor in jail.
Columbo also rarely seems to carry a gun, and is never required to exercise physical force, although in the episodes "How to Dial a Murder", "R.I.P. Mrs. Columbo" and "Columbo Goes to the Guillotine" he allows himself, as part of the solution, to place himself in a predicament in which the killer thought he or she would kill the Lieutenant and escape. In the 1975 episode "Forgotten Lady" it is revealed that he doesn't carry his gun - he says that he keeps it "down town" and has failed to attend his six-monthly pistol practice at the department's firing range for the past ten years. When Internal Affairs threaten to pull his badge for the lapse, he persuades a colleague to take the test for him, admitting that he "can't hit the target". He does, however, carry a gun for his work in 1992's "No Time to Die" and 1994's "Undercover" (even threatening someone with it in the latter), both of which are based on Ed McBain novels.
The character of Columbo was created by William Link, who claimed that Columbo was partially inspired by Crime and Punishment character Porfiry Petrovich as well as G. K. Chesterton's humble clerical detective Father Brown. Other sources claim Columbo's character is also influenced by Inspector Fichet from the 1955 French suspense-thriller Les Diaboliques.
Police Lieutenant Columbo is a shabbily-dressed, seemingly slow-witted police detective whose fumbling, overly polite manner makes him an unlikely choice to solve any crime, let alone a complex murder. However, despite his demeanor, Columbo is actually a brilliant detective with an eye for minute details and the ability to piece together seemingly unrelated incidents and information to solve crimes. Several of the killers have expressed their opinion on this apparent dichotomy to Columbo, including Dr. Ray Flemming ("Prescription: Murder"), Leslie Williams ("Ransom for a Dead Man") and Emmett Clayton ("The Most Dangerous Match").
Columbo usually zeroes in quickly on a prime suspect, often lulling that person into a false sense of security by conveying the impression that he does not suspect him or her, or actually suspects someone else. Columbo sets up circumstances which encourage them, in their newfound hubris, to incriminate themselves. Columbo's signature interrogation technique is to conduct a friendly and seemingly innocuous interview, politely conclude it and exit the scene, only to stop in the doorway or return moments later and ask, "Just one more thing..." (also called the false exit), which is always a jarring question regarding an inconsistency in either the crime scene or the suspect's alibi. The banality of the interview, combined with Columbo's ostensible absentmindedness and seeming incompetence, encourage the suspect to feel he or she is safe. Columbo's "one more thing" is the first clue that this is not the case. Columbo may pretend to "befriend" a suspect, making them believe that he is investigating another individual and enlisting the suspect's "aid" in gathering information. Thus suspects inevitably let down their guard because they are "working with" Columbo. In the end, most of the killers are stunned or chagrined. Others are worn out and almost relieved when the charade is finally over.
"Death Lends a Hand" first established that Columbo does not carry a gun. He has such low confidence in his ability to pass a routine departmental marksmanship test that in the episode "Forgotten Lady", he convinces a fellow officer to take the test for him, saying he himself could never hit the target. He rarely visits the Police Headquarters in Downtown Los Angeles, and in fact some members of the Department have never seen him there, a criticism to which he responds in the episode "Forgotten Lady" by commenting, "That's rarely where the murders take place!"
The following details of Columbo's life have been gleaned from statements the character made himself on the show, although in numerous cases it was apparently to establish a rapport with someone of interest, or occasionally speaking to someone unrelated to the investigation, as when he mentioned his mother-in-law to his veterinarian in "The Most Dangerous Match".
Columbo was born and raised in New York City in a neighborhood near Chinatown. In the episode "Murder Under Glass", he reveals that he ate more egg rolls than cannelloni in his childhood. He is Italian on both sides. The Columbo household included the future police officer's grandfather, parents, five brothers, one named George, and a sister. His father wore glasses and did the cooking when his mother was in the hospital having another baby. His grandfather "was a tailgunner on a beer truck during Prohibition" and let him stomp the grapes when they made wine in the cellar. In "No Time to Die", he attends the wedding of his nephew, who is also a police officer. He mentions his wife frequently, and once stated he employs her opinion on his ideas. In "Short Fuse", he states his wife's younger brother is a photography buff, and in "Blueprint for Murder", he says he has a brother-in-law who is an attorney. In "Requiem for a Falling Star", he tells the murderer, a famous actress named Nora Chandler, that he has a brother-in-law named George, and has her speak to him over the phone, although to whom she is really speaking is unascertainable.
At the end of "Dead Weight", he states that he has a niece named Cynthia, who is the daughter of his wife's sister. They may or may not have children; in two scenes in "Any Old Port in a Storm", he refers to the difficulty of getting a babysitter. He also mentions in that episode taking his wife and child on a picnic, and alludes to his child in "The Most Crucial Game". In "Rest In Peace, Mrs. Columbo" he claimed he and his wife didn't have any children, although in the Mrs. Columbo series (spinoff) there is a daughter, Jenny. Falk once stated during an interview on Inside the Actor's Studio that he wasn't truly sure how many relatives Columbo had aside from his wife.
Columbo's father, who never earned more than $5,000 a year and bought only one new car in his life, taught him how to play pool, an obsession that stuck with the future detective. His boyhood hero was Joe DiMaggio, and he also liked gangster pictures. Hardly a model child, Columbo broke street lamps, played pinball and ran with a crowd of boys that enjoyed a good prank. The trick of putting a potato in a car exhaust — which purportedly prevents the car from starting without causing permanent damage — served well on one of his cases. He jokes that he became a cop in part to make up for these juvenile pranks.
In high school, he dropped chemistry and took wood shop. While dating a girl named Theresa in high school, he met his future wife. After serving in the Army during the Korean War, Columbo joined the New York City police force and was assigned to the 12th precinct. He trained under Sergeant Gilhooley, a genial Irishman who tried to teach him the game of darts. He moved to Los Angeles in 1958.
In "The Bye-Bye Sky High I.Q. Murder Case," a murder suspect who possessed a genius-level intellect believed that Columbo's intellect was on a par with his own. During a conversation with the suspect, Columbo revealed, "All my life I kept running into smart people. I don't just mean smart like you and the people in this house. You know what I mean," implying that he frequently had to compete against people who were either better-looking, more physically fit, from better socio-economic backgrounds, or more politically savvy. He added, "I could tell right away that it wasn't gonna be easy making detective as long as they were around," but determined that he could even the odds by working harder than any of them, reading all of the required books and paying attention to every detail.
His trademark costume (raincoat over a two-piece suit, with a bone-colored shirt and a rayon tie) never varies from case to case or year to year. When on duty he is never seen without it, except in rare cases when circumstances (such as a formal event) require alternate attire. He takes his "uniform" so seriously that in the episode "Troubled Waters", after a murder was committed while he is enjoying a Mexican cruise with his wife, Columbo changed out of his cruisewear and wore his familiar suit exclusively until the case was solved.
Columbo is prone to airsickness and seasickness, and he cannot swim, though he has been known to row a boat. He is squeamish, and does not like hospitals or autopsies, or even looking at graphic photographs of murders ("Dagger of the Mind"). His squeamishness at hospitals, which includes an aversion to viewing surgical procedures or even watching someone given a needle, was displayed in "A Stitch in Crime". He claims to be afraid of heights, once remarking to an FAA investigator who offered him a job, "I don't even like being this tall." ("Swan Song", 1974). In "Dead Weight", when General Hollister (Eddie Albert) comments on Columbo's seasickness by asking why someone with the name "Columbo" would not be at home on a boat, the detective responds, "It must have been another branch of the family."
Columbo, although a policeman, does not carry a gun, but keeps it at LAPD Police Headquarters in Downtown Los Angeles, although on several episodes ("Murder under Glass", "How to Dial a Murder", and "Rest in Peace, Mrs. Columbo") the killer attempted to kill Columbo. He doesn't carry a firearm because he claims he hates guns and is a horrible shot, i.e. if he fired a gun off the end of a dock, he couldn't hit the water. He carries a gun only in "No Time To Die" and "Undercover".
His favorite food is chili with crackers, which he eats at a greasy spoon named Barney's Beanery, though in later episodes he is found eating chili at various different places, each one at which he is indicated to be a "regular". He drinks black coffee and has been known to have the occasional beer, or a glass of wine or spirits (i.e. he drinks bourbon with Dr. Ray Flemming in "Prescription: Murder"). He is also not above sharing one last drink with someone he is about to put away (i.e. "Requiem for a Falling Star", "Any Old Port in a Storm").
When called to a case in the early hours he brings a hard-boiled egg to serve as his breakfast. He loves cigars (usually of the stubby, very smelly, "Toscano" variety), which he smokes regularly (although more than once he gives up smoking during the series, only to restart in the next episode). His shoe size is referred to as "10 1/2 or 11" in "By Dawn's Early Light".
In several episodes he is accompanied by his dog, a basset hound whose unkempt appearance seems to match Columbo's own (as well as his well-worn car). And like the Columbo character himself, there is some question as to the dog's name. He is frequently referred to simply as "Dog".
In almost every episode of the ABC revival he is heard whistling the children's song "This Old Man". If he does not whistle it, it appears somewhere else, such as in the underscore. Its significance comes from the line "knick knack paddywhack, give a dog a bone" in the lyrics, since Columbo's standard tactic is to gnaw at a case like a dog would to a bone. In "How to Dial a Murder" he says that he loves billiards, and is seen playing pool in "Ransom for a Dead Man" and "The Greenhouse Jungle". He considers the comedian W. C. Fields a genius, and Citizen Kane a terrific movie (in "How to Dial a Murder").
In the 1971 episode "Dead Weight", when Columbo introduces himself to General Hollister the audience is shown a brief close-up of Columbo's badge and warrant card, complete with signature, which appears to read "Frank Columbo". The same ID badge and warrant card is seen in numerous other episodes, and the signature "Frank Columbo" is clearly visible in the season 5 episode "A Matter of Honor".
Universal Studios, in the boxset release of seasons 1-4 under their Playback label, included a picture of Columbo's police badge on the back of the box, with signature "Frank Columbo" and the name "Lt Frank Columbo" in type. This appears to be a different badge from the one seen in "Dead Weight", with a different signature. However, when Columbo is explicitly asked if he has a first name in season 4 episode By Dawn's Early Light, he just dispassionately answers back that he does, but the only person who uses it is his wife.
In the season 12 episode Undercover, Columbo is asked once again what his first name is, to which he emphatically answers, "Lieutenant," a sentiment echoed by actor Peter Falk and creators Richard Levinson and William Link.