The inspiration for famous fictional detectives is a topic of great interest among fans of the genre and, to a large extent, the general public as well. So, where do writers come up with their ideas about the often peculiar personality traits and the methods of such engaging characters?

As it turns out, most are based on either actual people or members of their own ranks: fellow fictional detectives. As this list of 10 inspirations for famous fictional detectives shows, there is good reason for the enduring curiosity about the origins of these engaging sleuths.

Related: 10 Legendary Exploits Of The Pinkerton Detective Agency

10 The Right Reverend Monsignor John O’Connor and Father Brown

Father Brown, the humble Roman Catholic priest, solves crimes based on his understanding of human nature as illuminated by his Christian faith as much as he does by his analyses of clues. As such, he remains as popular today as he was when G. K. Chesterton (1874-1936) first introduced him to the world in his 1910 short story “The Blue Cross.” The character has not only appeared in several of Chesterton’s own volumes but also in several movies and television series. Currently, he is the protagonist of the BBC One series Father Brown, starring Mark Williams, which is now in its ninth season.

The inspiration for this enduring character was himself a man of the cloth, the Right Reverend Monsignor John O’Connor (1870-1952). And he taught Chesterton a lesson the famous writer would never forget. After a spirited philosophical discussion with two Cambridge University students, during which Chesterton was present, O’Connor retired for the evening. The students then admitted that the clergyman was, indeed, a wise and brilliant man but, due to his vocation, most likely rather “insulated and naive.”

Chesterton was much amused by their opinion, having been earlier shocked at learning just how much O’Connor knew about “certain perverted practices.” This, of course, was the result of his having heard the confessions of those who had performed such acts. Chesterton had found a model for his own priest-detective, who would solve mysteries by practicing the arts of both the rational detective and the spiritual priest.^[1]

9 Dr. Joseph Bell and Sherlock Holmes

In an interview with The Strand magazine in which his short stories concerning his world-famous detective were published from 1887 to 1927, as well as in radio interviews and his 1923 autobiography Memories and Adventures, Sir Arthur Conan Doyle (1859-1930) explains the origin of Sherlock Holmes. During his student days, Doyle served as a clerk at the Edinburgh Royal Infirmary for the surgeon who became his mentor, Dr. Joseph Bell (1837-1911).

In this capacity, Doyle was able to observe how Bell interacted with his outpatients and learned that the physician was able to discover more about them by his own observations and inquiries than Doyle had obtained by questioning them directly before their appointments occurred. As a result of seeing Bell at work, Doyle wrote, “I used and amplified his methods when in later life I tried to build up a scientific detective who solved cases on his own merits and not through the folly of the criminal.”^[2]

8 Jacques Hornais and Hercule Poirot

Philosophers warn us not to confuse correlation with causation. Coincidences may be intriguing, but they don’t prove anything. Still, there could be a cause-effect connection between such incidents. The problem is that such a link cannot be demonstrated. Nevertheless, the striking coincidences between Agatha Christie’s possible acquaintance with refugee Jacques Hornais (1857-1944), a Belgian gendarme whose actual surname was Hamoir, and the detective Hercule Poirot she would later create are suggestive, indeed. Not only are they both Belgian, but they are also detectives—and there is a striking resemblance between Hornais and Poirot, whom Christie (1890-1976) describes as exhibiting a “stiff” bearing and wearing a mustache.

There is more reason to suppose that Christie may have modeled Poirot on Hornais. In her autobiography, the author herself muses, “We had quite a colony of Belgian refugees living in the parish of Tor. Why not make my detective a Belgian? I thought. There were all types of refugees. How about a refugee police officer? A retired police officer.” Despite the lack of definitive proof, the possibility that the refugee Belgian police officer inspired Christie’s Belgian detective is intriguing enough to warrant further investigation.^[3]

7 Eugène François Vidocq and C. Auguste Dupin

Despite the brevity of his life, Edgar Allan Poe (1809-1849) was not only productive, but he was also inventive, creating both the modern psychological horror story and the amateur detective story that would become the model for the detective fiction that followed. His detective, C. Auguste Dupin, made his debut in Poe’s 1841 short story “The Murders in the Rue Morgue” and reappeared in two subsequent stories, “The Mystery of Marie Roget” and “The Purloined Letter.” As Sir Arthur Conan Doyle points out, “There is no doubt that in the Dupin tales, Poe created the basic template for the detective stories of the future.” However, Doyle takes issue with Dupin’s flat, lackluster character.

Poe’s own source was Eugène François Vidocq (1775-1857), who lived in France at a time during which neither France nor Britain had either police forces or detectives. It was not until the 1820s that the Sûreté, or “French crime bureau,” was formed and not for over two decades later, in 1842, that London’s Metropolitan Police (aka Scotland Yard) added detectives to its force. Lacking a law enforcement source for a model, Poe based Dupin on Vidocq, the former criminal mastermind who’d reinvented himself as a private detective after serving as the Sûreté’s chief. According to Doyle, Poe used “the folly of the criminal [to] build up a scientific detective who solved cases on his own merits.”

A New York Times article summarizes Vidocq’s contributions to criminology. Long before such matters were customary in police work, he was looking into fingerprinting, ballistics, blood tests and the use of science to fight criminals.^[4]

6 Jim Grant, Lawrence Dallaglio, and Jack Reacher

The protagonist of Lee Child’s thrillers, Jack Reacher, is derived from a mixture of sources, including Child himself. According to Bryan Curtis, Child (the pen name of Jim Grant) is, like Reacher, a former U.S. Army military police officer who drinks an excessive amount of coffee every day, chain smokes, wears jeans and a T-shirt, and tends to be taciturn. Reacher, it so happens, is also the same height as his creator, “six-foot-five.” However, Reacher’s size, like his appearance, is also based on that of former professional soccer player Lawrence Dallaglio, who stands in at six-feet-four. Perhaps with Dallaglio in mind, Child has described Reacher’s face as looking “like it had been chipped out of rock by a sculptor who had ability but not much time.”

In developing Reacher’s character, Child used multiple sources, including stories of the knight-errant, the mysterious stranger, the Japanese ronin myth, and Robin Hood, a type of “character he says, that, “forced out of Europe as Europe became more densely populated and more civilized,” migrated to the American frontier.^[5]

5 Dave Toschi, “Dirty” Harry Callahan, and Frank Bullitt

Clint Eastwood’s Inspector “Dirty” Harry Callahan, who appears in Dirty Harry (1971) and four other gilms, along with Steve McQueen’s Lieutenant Frank Bullitt, of Bullitt (1968), are both based on the same person, the San Francisco Police Department’s Inspector David Toschi (1931-2018).
https://www.sfchronicle.com/news/article/SF-cop-who-hunted-Zodiac-killer-dies-Dave-Toschi-12488886.php
According to Kevin Fagan, it was Toschi’s “penchant for bow ties, snappy trench coats and the quick-draw holster for his .38-caliber pistol [that] drew the attention of Steve McQueen (1930-1980), who patterned his character after” the dapper detective, and Clint Eastwood’s Dirty Harry character was also “partially inspired by him.”

Eastwood got the role after Frank Sinatra (1915-1998) and Paul Newman (1925-2008), the initial choices for the part, turned them down. Sinatra because an injury to a tendon in his hand made it painful to hold a gun, and Newman because he “objected to its politics.” Ironically, Toschi seemed to regard Eastwood as an unlikely choice for the part. Despite his stardom, Toschi said, Eastwood’s detective impressed him as “an almost shy person [dressed in] faded jeans, a T-shirt, [and] white tennis shoes.”^[6]

4 Porfiry Petrovich, Father Brown, and Columbo

Bing Crosby (1903-1977) would have played the disheveled, one-eyed, cigar-chomping police detective in the wrinkled trench coat had William Link (1933-2020) and Richard Levinson (1934-1987), the creators of Frank Columbo, had their way. However, the part went, instead, to Peter Falk (1927-2011). The actor’s portrayal of the seemingly scatterbrained, humble inspector created as enduring a character as exists in the history of Hollywood. To create their star detective, Link and Levinson based Columbo on both Porfiry Petrovich and Father Brown.

As childhood friends, Link and Levinson had long enjoyed detective stories and mysteries. They were fans of Crime and Punishment (1866) by Fyodor Dostoevsky (1821-1881), from which they borrowed aspects of Porfiry Petrovich, and of G. K. Chesterton, whose Father Brown provided both Columbo’s humble demeanor and his ability to seemingly disappear among others who thought the cop apparently irrelevant. As Shaun Curran points out in his online BBC Culture article, Columbo’s “distinctive posture, exaggerated hand gesticulations and a contrived forgetfulness—his habit of leaving a room, only to return having remembered ‘just one more thing’ became his trademark.”^[7]

3 Inspector Clouseau, Lt. Columbo, Sherlock Holmes, Porfiry Petrovich, and Adrian Monk

Adrian Monk, of the television series Monk, was based on more other fictional detectives than most of his peers. The first inspiration for the obsessive-compulsive detective was inept Inspector Clouseau of Pink Panther fame. However, the French detective was not Monk’s creators’ inspiration. Instead, it was that of an ABC executive “looking for an Inspector Clouseau-type show.” It was co-creator David Hoberman who thought up a brainy investigator who not only had a welter of personal problems but also suffered from an obsessive-compulsive disorder, as Hoberman did himself. Although the condition was never officially diagnosed, Hoberman related, Monk’s compulsion to “walk on cracks [and] to touch poles” was inspired by Hoberman’s own perceived need to do so.

Monk is also influenced by Sir Arthur Conan Doyle’s Sherlock Holmes and by Columbo, writes Alessandra Stanley. She contends that Monk is cast, in episodes featuring his brother Ambrose, as Sherlock to his “smarter” sibling Mycroft. Also, as “class [distinctions] drove suspects to underestimate Lieutenant Columbo, Peter Falk’s coarse accent and humble demeanor always lulled rich, sophisticated killers into a false sense of superiority.” Both Monk and Columbo, she said, in turn, are influenced by Dostoevsky’s courteous, plodding investigator, Porfiry Petrovich.^[8]

2 William Oliver Wallace and Jonathan Creek

David Renwick’s Jonathan Creek, who creates magic tricks for the magician who performs them, also acts, at times, as an amateur detective. Not surprisingly, given his area of expertise, Creek was based on professional magician William Oliver Wallace (1929-2009), who went by the stage name Ali Bongo. The flamboyant magician was a superb choice for the television series’ magic consultant.

As an online article in The Guardian points out, Wallace’s interest in magic began at age five. After a stint in the Royal Army Pay Corps, during which he co-wrote Naafi shows in which he appeared, he was convinced that he had the experience and skills to succeed in the entertainment business. So he founded the Medway Magic Society, appearing as Ali Bongo, which, at first, included dialogue but later became a pantomime act. Subsequently, he landed the position of chief consultant for Thames TV’s David Noxon’s Magic Box due to his “encyclopedic” knowledge of magic.^[9]

1 James Bond and Thomas Magnum

Agent 007, aka James Bond, is the quintessential British spy. Whether portrayed by Sean Connery, David Niven, George Lazenby, Roger Moore, Timothy Dalton, Pierce Brosnan, or Daniel Craig, the debonair agent of Her Majesty’s Secret Service, created by Ian Fleming (1908-1964), is well-known around the world. It’s little wonder, then, that the creative team who created Thomas Sullivan Magnum IV initially wanted to model their character after Bond.

Instead, the team accepted Tom Selleck’s suggestion to make his character more an ordinary kind of guy, an average Joe, but one who is also charming—and mustachioed. In fact, as writer Dana Sivan points out, Selleck’s mustache, one of both his and Magnum’s most iconic features, was “entered [into] the International Mustache Hall of Fame.”^[10]

In movies people hire private detectives to catch cheating spouses or find missing people all the time. In real life that goes on, but they also get hired by corporate clients to investigate competitors, clients, and even their own staff members for a variety of reasons. In most cases this is probably pretty standard stuff; maybe there is a fear of corporate espionage or someone is stealing. But sometimes the reasons can be almost unbelievable. 

10. General Motors Hired Detectives to Discredit Ralph Nader

In 1965, Ralph Nader wrote the book “Unsafe at Any Speed,” which took the auto industry to task for putting profit over safety and accused them of knowingly putting people at risk in unsafe vehicles. One of his big targets was the Chevy Corsair, made by General Motors and the company was not happy at all.

General Motors responded by hiring private detectives to spy on Nader and find evidence of anything they could use to discredit him, even if that meant manufacturing that evidence. First, they tried to seduce him with a prostitute but he turned her down.  Later they attempted to discredit him by suggesting he was homosexual, harassing his neighbors and others with leading questions about his sexuality in a time when being gay would absolutely have been viewed as something discrediting. 

The detectives were caught and the whole sordid scheme came out during congressional hearings which made General Motors look even worse but did lead to the rise of seatbelts and other safety features. 

9. Progressive Insurance Spied on Customers in Church

Insurance companies have a bad reputation at the best of times and if you don’t have your own negative experience dealing with one, you probably know someone who does. So when you find out a company like Progressive took the time to spy on people in church, it definitely doesn’t help their image. 

Progressive hired detectives to go to the church of a couple who were suing the insurer and spy on them. They became church members and even joined a private support group for people who were working through serious personal issues like drug addictions and abortions. They taped those meetings to get dirt on the couple. This led to the people filing another lawsuit against the company as well as the detectives.

The head of Progressive apologized publicly but the company also denied they did anything wrong in legal filings. 

8. Pillow Pets Hired Detectives to Hunt Down Counterfeit Pillows

Pillow Pets first arrived on the toy scene in the early 2000s. They look like typical stuffed animals with the added twist that you can convert them into pillows. They became hugely popular and by 2009 they had $7 million in gross sales. As with anything popular, that fame soon brought knock offs out of the woodwork.

By 2011, US Marshals were involved in the Pillow Pet world, hunting down counterfeits. Fake Pillow Pets had been flooding the market so the company had hired private detectives to track down the source of the fakes. 

Their efforts led marshals to a New York warehouse owned by a rival toy company. The whole endeavor was kept under lock and key so the other company wouldn’t get wind of it and when marshals arrived, they seized 17,000 fakes from the warehouse. 

7. New York Ice Cream Trucks Spy On Each Other

Ice cream is a fun summer treat, but only if you’re the person eating it. If you’re an ice cream seller in New York, then the entire game can become cutthroat and brutal. In 2017, the cool world of ice cream became heated when Mr. Softee went to war against rival ice cream seller New York Ice Cream.

Both companies operate out of ice cream trucks but Mister Softee was accusing the other company of operating fraudulent Mister Softee trucks. About a half dozen detectives were employed by Mister Softee to spy on the competition in what ended up becoming so heated that the detectives were being threatened with pipes. 

New York Ice Cream, started by a previous Mister Softee employee, was accused of using the Mister Softee Logo and even their trademarked jingle. A judge ruled in Mister Softee’s favor that the competition had to stop. 

6. Lenny Dykstra Hired Investigators to Blackmail MLB Umpires

Former professional baseball player Lenny Dykstra has a checkered past which includes some arrests and challenging people to fights on social media in addition to fraud and even grand theft auto.  His aggressive behavior is nothing new, however, and he readily admits to engaging in some seriously questionable behavior even back in his heyday.

Back in 2015, Dykstra admitted that he had hired investigators to dig up dirt on major league umpires. He did it specifically towards the goal of blackmailing them so they’d be more inclined to make calls in his favor during games like widening his strike zone so he could get more walks than strikeouts. You may recognize that as cheating. Really elaborate cheating. 

He says he paid $500,000 and then points out that, after he did that, he led the league in walks for two years to demonstrate his plan worked. 

5. Uber Has a History of Hiring Security Firms to Investigate Critics

Uber has only been around since 2009 but the company has had a huge impact on the world. The ride share idea has become ubiquitous all over the globe, and the company posted $17.4 billion in revenue during 2021. They have not, however, been without scandal during that time. Accusations of sexual assault are numerous, others including obstruction of justice, unfair firing and so much more. And with all of those accusations being tossed around, maybe it’s not a surprise that the company hires investigators to look into their accusers. 

When the company was accused of violating antitrust laws, Uber hired a firm staffed by former CIA officials to look into not just the plaintiffs but the lawyers as well. The investigation was exposed, and it blew up in Uber’s face with the judge in the original case saying it gave a “reasonable basis to suspect the perpetration of fraud.”

In 2014, in the middle of what seemed to be a PR dinner with journalists and people like actor Ed Norton, an Uber vice-president openly talked about hiring investigators to dig up dirt on journalists who criticized the company. He immediately tried to backpedal after the dinner.

4. Rockstar Games Hired A Detective To Locate a Musician’s Family

As we’ve seen so far, in most cases a private investigator is hired to do some fairly unsavory work but that doesn’t have to always be the case. They’re not nefarious by definition, after all, it’s just that most things only require investigation because people are trying to dig into secrets or unscrupulous acts. However, Rockstar Games, the company behind the extremely popular Grand Theft Auto franchise, has shown that some good work can be done with the help of investigators as well. 

The Grand Theft Auto series is notable for the music they include and GTA IV included a song called “Walk the Night“ that was released by a group called the Skatt Bros. in 1979. The game was huge in ways no video game ever had been before. It broke sales records and has made over $2 billion since its release. Some Of that money filters down to the musicians whose music was featured and that meant the Skatt Bros were looking at a pay day. But the problem was that the songwriter, Sean Delaney, had died in 2003. 

The publishing shares that Delaney owned had gone to his brother, sister and a nephew, but no one knew where they were. Rockstar did right by Delaney and, rather than letting it go, they hired an investigator to track down his relatives. The investigator had to travel to the city of Orum, Utah, with a population under 100,000, to find them and make sure they got what was owed. 

3. Municipal Governments in Australia Hire Investigators to Have Sex With Prostitutes 

Imagine trying to explain your job to anyone and get them to take you seriously if you were one of the investigators hired by Australian authorities to hire prostitutes and then report back about the experience. As unbelievable as it sounds, it was a real thing, arguably funded by taxpayer money.

In 2007, officials in Sydney were looking to crack down on illegal brothers within the city. Somewhere north of $16,000 was paid over three years to get investigators to go through the entire process from beginning to end so that the council will have irrefutable evidence of the illegal acts. Brothels are legal in Australia, but they have to be legal brothels, if that makes sense. Just like you can’t have an unlicensed bar in America, you can’t have an unlicensed brothel in Australia. 

As late as 2019 investigators were still being hired to go to massage parlors and see if there were sexual services being offered in addition to the legal activities. The work involves either having acts performed by employees or, if it’s part of the job, having full sex with the employees that are being investigated. 

2. A Spanish Town Hired a Detective To Spy on Pet Owners

No one likes a dog owner who doesn’t clean up after their dog. It’s a scourge of the modern world but, unless you catch someone in the act of leaving it, there’s not much to be done about it. But for one town in Spain, that was not good enough. 

Colmenar Viejo invested money in hiring a detective back in 2014 to roam the streets undercover, complete with a camera, to get evidence The detectives job wasn’t to stop anyone if he caught them ignoring their duties as a pet owner. Instead, they would just gather proof and give it to the police. The pet owners could then expect a respectable fine of €750 after the fact.  That’s actually a mild fine compared to larger cities like Madrid and Barcelona where the fines are double that. 

The detective seemed to be a sort of last resort effort as the already steep fines had not proven to be enough to convince residents to clean up. So the added threat of people knowing they were being watched might have done the trick. 

1. A California Water District Hired investigators to Track Tom Selleck’s Water Use

California summers have been harsh for a number of years now with droughts and fires becoming more and more commonplace. Many communities have had to institute rules over water use in an effort to conserve what is available. 

Actor Tom Selleck, best known for Magnum PI in the ’80s, has a ranch in California and was accused in 2015 of using more than his fair share of water, illegally taking it from the Calleguas district. The Calleguas Municipal Water District hired a private investigator and determined that a truck from Selleck’s ranch had been tapping a hydrant on several occasions between 2013 and 2015.

Reps for Selleck said the water was from a construction site and the actor paid for it rather than stealing it, but the district pointed out you can’t just buy water from someone else like that. In the end, Selleck agreed to pay the district just over $21,000 to settle the lawsuit.