Early Detective Agency Advertising And
Private Investigative Trends From The Past
By Ralph D Thomas

Why study history? Because it almost always repeats itself. The private investigative profession is rich in history when it comes to past trends, marketing and advertising and we can always learn something from studying this. The Spy And Private-Eye Museum has collected an assortment of artifacts from the past along these lines and I thought I would share them with you.

Blotter Ads, Early 1900's- A Trend From The Past

Blotter ads were oversized business cards printed on very heavy cardboard. They were very popular advertising mediums in the early 1900's and were considered prestigious. They were always printed in full color and were expensive to do. The blotter ad on the left is from E. O. Ream Investigating And Detective Bureau, Reading, PA. from the 1920's. The blotter ad on the right is from Universal Detective Bureau, St Augustine, Florida , 1951. You can click on the links above to see larger images of these blotter ads, obtain more information on those agencies and see recent photos of the actual buildings these two agencies were in which are still standing today. Today's use of this would be four color ads, four color business cards and advertising specialties. People tend to keep things that are unique and unusual.

Fred Otash Hollywood Private Investigator,
Several Space Ads On Fred Otash, 1960's

Fred Otash Detective Bureau Ad, November 1960
Fred Otash was a very famous private detective of the 1960's that most of the known Hollywood celebrities used. Upon the death of Marilyn Monroe, Peter Lawford called this man. Fred Otash operated at a time in Hollywood before no-fault divorces in which almost everyone who was anyone hired a private-eye if they were getting a divorce. The phone book was full of them. You can click on the above link to see larger images of the ads and learn more about Fred Otash.

Powell National Detective Agency Ad,
Denver Colorado, And The Dictograph Trend,1931

Note the fact that Powell National Detective Agency offered what was called Dictograph Services.Click on the blue link to learn all about what the Detective Dictograph was. Since Dictograph services is listed first and in all caps, you can assume this was a big thing for the agency. The Dictograph at the time was a modern, new age, high tech audio listening device that was the marvel of it's time. The agency was founded, according to the ad; in 1910. In 1931, they had thus been in business for 21 years. Mr. Powell was likely very well established. Note the wordage "Frequently Using Camera" and "Conducted Without Publicity". It's interesting to note that Powell National Detective Agency listed "employee investigations for firms and corporations" at this time period. In this era, surveillance was called shadowing. Note that this ad listed a main number and then three separate telephone numbers below for after hours calls. William Powell's home address is listed in the 1931 Denver phone book as (and we quote)
Powell, William, r
W 12th And Wadsworth Av TAbor 6975

Tin Signs And A Trend From The Past
For many decades private investigative services made very good income by offering packaged protection services for retail businesses. The packages consisted of offering to investigate and recover any loss that might happen and provide security consulting type services. Most of the larger agencies had tin signs made up that retailers could hang in their window notifying all that they were protected. These tin signs often stated that rewards were already in effect for any loss. These tin signs were also a very good way of advertising investigative services. You could often go into a business retail area which was almost always the main street down town and find a huge percentage of small businesses with signs like these hanging in their windows. For a long time, many agencies also offered burglar alarm services to go along with their security package. As centralized burglar alarm services came into being, law enforcement got much better and more organized, these types of services offered on a large scale by a private detective bureau died out. Here is a description of the signs listed above which you can click on to get bigger photos and more information about the signs and investigative agencies behind them.

Standard Secret Service Detective Bureau Sign, Philadelphia, Early 1900's

American Agency Private Investigation Sign, Birmingham, Al. 1950's

Pinkerton Detective Agency Jeweler's Security Alliance Protection Notice Sign 1800's


Central Identification And Investigative Bureau Letter Opener, 1941
Some things never change. The purpose of an advertising specialty is to get a client or potential client to keep something on their desk with your name, address and phone number right in front of them so they call you when they need you. What better product than a letter opener a potential client would keep on their desk. When an investigation is needed when the potential client is at their desk, who are they going to call?
Leonard Delue Secret Service Investigators Ad
Denver, 1931

In this time period, private investigative services were often called "Secret Service Investigators." Let's see what else we can quickly find out about Leonard Delue and his Secret Service Investigators from the ad. Note the logo. It's likely a combination of the Masonic Mason logo with a finger print in the middle. We checked and sure enough, Leonard Delue was a Mason in 1931. Note that Leonard Delue listed both his day office phone and night phone. Note also the phone numbers. In 1934, there was only a two digit prefix. KE-1397 would get the service during the day and FR-6348 would connect you at night to what was Leonard Delue's home phone. We checked a 1934 phone book for Denver and sure enough, there was a Leonard Delue listed at a home address (indicated with a "r" for residence) of 310 Colorado Blvd. with a phone number of FR-6348.

Another Fred Otash Ad, 1960's

Not the slogans. "Investigation Today Is A Complex Science." "Internationally Known Private Investigator." (That was certainly a true statement!) Also note that Otash listed his association memberships, CAPI and CII. Listed specilizations are interesting including motion picture and still photography, radio and tape recording, mini-photograpy, laboratory, closed circuit TV, complete recording facilities. The basics of this ad and it's type layout would be relevant today.

National Checking System And Detective Agenices in Memphis, 1961

Unlike places like Hollywood California, domestic and divorce cases was not a staple type of investigation everywhere in the USA in the early 1960's. Memphis, Tn. only listed a dozen private investigative agenices in the yellow pages. Only two of them had small display ads. None of them advertised divorce or domestic investigations as a service offered.

A Two Page Magazine Ad, Pinkrton's, 1963
Click here for a bigger view of the ad and more info.

Globe Detective Agency Advertising Lighter, 1950's
Here is a special advertising agency lighter from the 1950's that Globe International Detectives of Pa. gave away. It's typical of how investigative agencies in the 1950's promoted themselves.
Pinkerton National Detective Agency Testimonial Advertising Booklet, 1910

In 1910 Pinkerton National Detective Agency produced a promotional booklet that contained testimonials of various police departments that was 74 pages. The book was used to promote their services to banks. There was 65 testimonials in this promotional piece from 29 different states, Canada and England. You can click on the link above for larger view and more info.
Investigative Specializations In 1914
Frederick Wagner Detective Agency Course Ad, 1914

To the left are photos of advertising mailing material sent out by Frederick Wagner Detective Agency for a course on becoming a private detective dated Feb. 7, 1914. It states in part how one can enter the profession and earn $150.00 to $300.00 a month. It also states and I quote, " The full complete Detective Course is only $15.00 but they expect the price to rise to $25 soon so do not delay and enroll." Promo material teaches fifty different methods including, shadowing, disguises, circus detective, bogus employees, pool sharks and fire bugs. You can click on link above for close ups of material and more information about it which will also tell you about the major types of private investigations in 1914.

Reward And Notice Posters -Tends From The Past
Prior to the establishment of the Federal Bureau Of Investigation, it was mainly private detective bureaus that were considered a national police force. During this time period, Pinkerton National Detective Agency and then Burns International Detective Agency dominated the market place. Reward and wanted posters as well as notice signs were an established part of conducting the investigation. Detective bureaus had a large market place in big cities for solving thefts, finding missing persons and recovering assets. It was very common practice to have hundreds of notice and reward posters printed up and circulated. That was also a good way for detective bureaus to advertise and get their named out. You can click on the link above to review an extensive collection of these old wanted, reward and notice posters.

William J. Burns International Detective Agency, Inc. Letterhead 1921
Note the fact that it listed some major clients and the phone number of 1775.
Also note the contact via a cable address. A cable address was communications and contact through the telegraph ( see the presentation: The Telegraph, Private Investigators, Spies And Telegraph Eavesdropping )

The Spy Of The Rebellion By Allen Pinkerton
Book And Ad, 1883

Allen Pinkerton's book, The Spy Of The Rebellion; was published in the late 1800's. It starts out with information about Lincoln's Presidential election, the attempted assassination of Lincoln that Pinkerton prevented and his involvement with the creation of the Secret Service as well as his spying activity during the Civil War. This page gives you a photo of the book and a four page ad about the book and how to become a salesman for it.

Various Ads From University of Applied Science
Finger Print And Secret Intelligence Service Course, 1923

This course was one of the most successful detective courses that ever operated in the United States. The University Of Applied Science ran ads from the 1910's all the way into the 1960's. It successfully operated for about 60 years. Fingerprinting technology was hyped because when the course first started, fingerprint methods were the latest and most modern detection method there was. The ability to identify someone with fingerprints was a wonder back then. The private investigation trade was often called "Secret Intelligence Services" back in the 1910's. You can click on the link above and obtain more information about this long-running training program and get bigger photos of the ads that ran.

Pinkerton Letterhead In Early 1900's
Note that this office hyped the fact that they were "connected by phone"
Rumor has it that Allen Pinkerton wouldn't use a telephone and thought they were useless.
In his hayday in the 1860's to the 1870's, he did use the telegraph ( see the presentation: The Telegraph, Private Investigators, Spies And Telegraph Eavesdropping ) a great deal, and
likely bugged them at various points. However, to him the telephone was something he
obviously didn't quite understand. It all fareness to Allen Pinkerton, he was quite aged by the time the telephone was invented. Who knows, maybe he figured out that they were too easy to bug. Then again, so was the telegraph.

Spears Investigation Bureau Ad 1953
Spears Investigation Bureau was located in Portland Oregon. In 1953, there were 13 investgiative services and four display ads listed in the Portland yellow page telephone direcrtory. The population of Portland in 1953 was about 70,500.To the right is their yellow page ad as it appeared in 1953. Note the logo making use of the Spear name. Note the Spears slogan "An Investigation Well Done Is A Case half Won." They specialized in "public and private" investigations. C. C. Spears was formly with the FBI and Army Air Corps Intellilgence. Like all ads of this time period, there were only two digits in the prefix of phone numbers and it was the custom to display them with letters (not numbers). The letters became words and you used the first two letters of the word. Thus BEacon was BE for BE-2567. You can click on the link above to see the other three display ads from the Portland 1953 yellow pages for private detectives.


Current Investigative Agency Marketing Techniques
I f you want to expand your investigative service and use effective marketing techniques that bring you more cases and more clients, check out this selection of current training material on how to do it and do it right the first time!

Ralph Thomas, Director
SpyTek Wholesale & SpyTek Authorized Dealer Program
Thomas Investigative Publications, Inc.
National Association Of Investigative Specialists, Inc.
Utrak, Inc. -Online GPS Tracking
PI Vintage- The Spy & Private-Eye Museum
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All materials including photos:
Copyright: 2006, Ralph D. Thomas