Historic Perspective: A Forensic Pioneer in Colorado
Written by Thomas W. Adair and Bruce Adams   

HISTORIANS of western photography are familiar with the work of Ed Tangen depicting early 20th Century life on the front range of the Rocky Mountains in Colorado. In the 45 years between 1906 and 1951, Tangen is known to have taken more than 16,000 photographs in this region, capturing the architecture, evolution of technology, and the rich social life surrounding that era.

What has been lost, at least to the law-enforcement community, is the profound contribution that Ed Tangen (Figure 1) made to the advancement of investigative sciences in Colorado. Ask any criminalist in Colorado about the career of Ed Tangen and you will probably receive only a blank stare. But his work should be appreciated by criminalists. And the fact that Tangen conducted his extraordinary work in the agricultural and mining town of Boulder, Colorado is all the more reason to applaud his work.

Figure 1—Self portrait of Ed Tangen, one of the earliest forensic photographers.
(Photo courtesy Colorado Historical Society)

In 2003, one of the authors of this article (Adams) was looking through photography books at the Jefferson County Public Library when he found a book about Tangen—Ed Tangen, The Pictureman—written by Tom Meier and published in 1994. The book is an excellent biography of the life and photographic work of a man few really seemed to know. The biography mainly highlights Tangen’s coverage of the region and its culture, but among the hundreds of photographs included in the book, there are 26 that depict Tangen’s work as a sheriff’s identification officer. People say that a picture is worth a thousand words. To the authors, this small collection of photographs indicated that Tangen’s forensic work was indeed special.

Meier has done an exceptional job in chronicling the life of Tangen. He was born Eivind Jensen Tangen on January 31, 1873 in the forested village of Elverum in eastern Norway. The Tangen family emigrated from Oslo to New York City in 1881 and shortly thereafter boarded a train to Chicago, Illinois. In 1890, when Tangen was 16, he and his two younger siblings became orphans. In 1892, Tangen was employed as a marble worker and within two years became a stonecutter.

The record of Tangen is blank from 1894 until 1903, when he established a portrait and frame studio in Boulder, Colorado. An entry in the 1938 edition of Who’s Who in Colorado listed his occupation from 1894 to 1900 as a “traveling photographer”. Tangen lived in a canvas-wall tent in the back yard of a residence in Boulder from 1909 until well into the 1940s.

He spent the next two decades documenting various aspects of Colorado society and culture, including the architecture, social events, and windows into the everyday lives of his fellow citizens. Tangen was also a commercial photographer for companies such as Western States Cutlery and photographed various consumer goods and store window displays. He was an avid mountaineer and life member of the Rocky Mountain Climber’s Club for which he was the “unofficial” photographer. Tangen was such an accomplished climber that certain features in the area—including a tunnel, a spring, rock towers, and several trails around Boulder—are named after him.

In 1923 Tangen’s career took an unexpected turn when someone, probably a sheriff’s deputy, came into his studio and requested his assistance in photographing a fingerprint. This encounter sparked a career that would leave an indelible mark on the Colorado forensic community. Tangen became passionate about photomicrography and forensic evidence. He quickly educated himself in the fields of fingerprints, footwear, questioned documents, toolmark identification, and ballistics. He undoubtedly subscribed, and later contributed articles, to The American Journal of Police Science. He also self-published several booklets on various techniques and case reviews. Tangen served as the Colorado state vice president for the International Association for Identification (IAI) from 1942 to 1943.

Over his 28-year career in law enforcement, Tangen worked cases throughout Colorado and the Rocky Mountain region. He established a steady working relationship with the Boulder County Sheriff’s Office and eventually his original photographic pursuits became secondary to his forensic work.

His employment with the sheriff’s office was an unusual relationship by today’s standards. Officially he was listed as an identification officer, and had an office in the basement of the courthouse. But he also maintained his own laboratory in a private building across the street. Like many photographers, Tangen retained custody of all his negatives, which included all of his crime-scene images.

Although he was a civilian, he carried a badge and a 9mm Luger pistol. One of his badges was a five-pointed star marked with the words Official Photographer. Another badge was inscribed with his name, the state seal, and the title Deputy Sheriff. He wore the typical attire of plainclothes lawmen of that era: a business suit and a necktie, together with vest, suspenders, and fedora-type hat.

Tangen seems to have gotten his equipment to crime scenes via car, train, walking, and even pack animals. He was known to take a portable darkroom tent and chemistry on pack mules when he traveled into the mountains and other remote locations.

To fully appreciate Tangen’s crime-fighting accomplishments, it is helpful to recall the time period of his work. He began his law-enforcement career shortly after World War I during the Roaring Twenties. He worked through the desperate times of the Great Depression in the 1930s and through the wartime strain on the home front during World War II in the 1940s. His self-taught forensic work was done in the days of hand-crank automobiles and passenger trains; during the Prohibition years of bootleggers and raids on illegal stills. He was working when long-distance communicating was done by telegram and when radio broadcasting was in its infancy. It was the time of gamblers, chicken thieves, and safecrackers—long before the birth of the FBI and the FBI laboratory.

We can only imagine the challenges and adversities that Tangen faced, especially when he was at crime scenes, using the forensic equipment and methods of his day. Take, for example, his crime-scene cameras: big, heavy, large-format-view cameras mounted on tall wooden tripods. He composed and focused his images manually with a bellows lens and a ground-glass viewer that displayed images upside down. He draped a dark cloth over his head to shade light from the viewer. To make flash photographs, he used a handheld, torch-like device consisting of a small open tray of ignitable flash powder atop a handle with a manual sparking mechanism. He composed and focused his picture, opened the camera shutter, ignited the powder for an explosive burning flash, and closed the shutter. The process was laborious and dangerous. Each flash produced an offensive cloud of smoke and soot. Tangen stubbornly continued to use this flash method throughout his career, even after the advent of flashbulbs.

Tangen worked tirelessly as an identification officer until his death in 1951 at the age of 78. After his death, his comparison microscope and some related equipment was purchased by the Boulder County Sheriff’s Office where it resides today. His collection of images, consisting of approximately 2,300 glass and film negatives, was purchased at auction by a collector. They were later sold to a museum in Texas and were finally transferred in 1999 to the Colorado Historical Society (CHS).

Of the 2,300 pictures in the Tangen collection, about 187 are related to crime-scene investigation and evidence photography. The authors of this article began a review of the entire CHS collection of Tangen negatives in 2004. The negatives were not organized by theme and the crime-scene images were randomly mixed into the collection. Great care and time was necessary in the handling of these fragile negatives and all review work was conducted over a two-year period at the CHS. Many of the descriptions for the crime-scene images were incorrectly labeled on the negative sleeve. This was not surprising as the volunteer staff that had reviewed some of the negatives did not have the proper experience or perspective to recognize forensic evidence such as magnified gunpowder, expended bullets, or cracked safes.

The negatives, undoubtedly just a glimpse into Tangen’s forensic work, suggest an unexpectedly professional approach to crime-scene work for a photographer in such a small valley community. By 1943, there were only four paid staff members—including Tangen—with the Boulder Sheriff’s Department. The records show that special deputy commissions were authorized to other individuals only on an as-needed basis. At this time, the population of Boulder County was fewer than 38,000 residents.

The technical skill seen in Tangen’s work is not surprising given his expertise in photography. The images suggest a surprising depth of investigative knowledge. While the number of photos taken at any particular scene was small by today’s standards, those images provide a window into the investigative techniques that were employed by Tangen and the police.

Tangen used his camera not only to document the conditions of the scene but also to tell a story of the event by showing reconstruction of the crime.

In one case, Tangen photographed trajectory strings in a shooting investigation (Figure 2). A spring gun had been rigged by the owner of a gas station to discharge at the pumps should anyone attempt to dispense fuel after hours. The gun had activated as a paying customer approached the pump at closing time, causing a near-fatal shooting.

Figure 2—The officer at the left is holding a trajectory string of the bullet flight path
in a spring-gun shooting at a gas station in May 1930.
(Photo courtesy Colorado Historical Society)

In another case, Tangen again used strings to document bullet trajectory in a residence (Figure 3). He took photo-graphs of a man (presumably either the homeowner or a detective playing the part) standing in a doorway holding a long gun along the bullet flight path. It is not known whether the depiction is demonstrating the bullet path from the suspect’s or the victim’s gun, but the photograph is interesting because it shows a deliberate attempt to reconstruct certain aspects of the crime for later presentation in court.

Figure 3—A 1927 reenactment to calculate the shooting trajectory in a residence.
(Photo courtesy Colorado Historical Society)

Tangen’s ability to produce detailed photomicrographs undoubtedly was an enormous benefit to the law-enforcement community and helped to inform and educate prosecutors, judges, and juries on subjects about which few were aware. For example:

In 1931, Tangen received pieces of cut wire from a cattleman’s fence along with a pair of pliers found at the suspect’s home. Tangen methodically examined the cut marks and determined that the pliers did in fact produce the cuts on the wire. He reproduced the cut marks photographically at 2,500-times actual size for court. The composite photographs of the cut wire and an exemplar of cut wire were presented in court. The jury subsequently reached a guilty verdict. This is believed to be the first criminal case in which this type of identification was accepted.

Tangen’s work in this case attracted the attention of J. Edgar Hoover at the Federal Bureau of Investigation (FBI). The FBI laboratory was created in 1932 and Director Hoover wrote a personal letter to Tangen on April 2, 1934 saying that he was “greatly interested” in the court exhibits prepared by Tangen and was “pleased” that they were accepted at trial. Over the years, Tangen made many similar court exhibits of fingerprints, shoes, tires, fired bullets, and firing-pin impressions.

We know from the published literature and items at the Boulder County Sheriff’s Office that Tangen maintained records with standards for comparison of fired cartridge casings, bullets and rifling, gunpowder types, and shot-shell pellets. He appeared to have a detailed cataloging system that would allow him to utilize this reference collection during casework. The Boulder County Sheriff’s Office still maintains a small collection of rim-fire cartridge casings in a numbered collection display box.

In October of 2004 and again in June of 2007, the authors interviewed Tangen’s co-worker, Dock Teegarden, who took over criminalistics at the Boulder Sheriff’s Office after Tangen’s death. In 1943, Tangen had a stroke while at work. After a two-month stint in the hospital, he returned to work at the sheriff’s office until his death in 1951. Tangen and Teegarden worked together for about six years at the end of Tangen’s career. Teegarden had come to the sheriff’s office in 1945 following military service in World War II. Tee-garden, now 88 years old, was a wellspring of information about the last years of Tangen’s life.

Teegarden related that Tangen never married or had children and kept few friends. He was eccentric and private and seemed to live a very regimented and Spartan lifestyle. He never owned a car. Instead, he would take the train to various cities for testimony or casework. In his later years, Tangen’s daily life was virtually limited to an area of two city blocks in downtown Boulder. He lived at the Albany Hotel and ate most of his meals at the Howard’s Cafe or at the hotel, all within two blocks of his office at the courthouse.

Teegarden shared many interesting observations relating to Tangen’s investigative work. He was believed to have one of only two ballistics microscopes in Colorado and one of only a few in the western United States.

To obtain test bullets, he constructed a wooden box approximately eight feet long with six-inch sides. There were slots of cardboard every 12 inches and wads of cotton waste (the kind used for packing journal boxes and bearings on trains) in between the cardboard sheets. He would fire a gun into the cotton waste and use the cardboard sheets to determine the bullet’s approx-imate location within the box. For large-caliber rifles like the 30.06, he would use a file and cut the casing open at the rear of the shoulder, then pour out enough gunpowder so that the bullet would be prevented from escaping the length of the box. Tangen test-fired hundreds of guns in this manner on the open roof of his laboratory across the street from the downtown courthouse square.

Tangen also processed items to recover latent fingerprints. Amazingly, Teegarden was still in possession of Tangen’s original fingerprint kit. The small leather pouch contained two camel-hair brushes and six vials of colored powders (Figure 4). One vial appeared to be a type of theft-detection powder. Tegarden also had a folding fingerprint loupe used by Tangen.

Figure 4—Recent close-up photo of Tangen's original fingerprint kit.
(Photo courtesy of the authors)

Photographic evidence shows that Tangen used plaster of Paris to cast shoe and tire impressions at crime scenes. A few of the casts appeared quite “clean,” indicating that they may have been made from snow impressions. Tangen also used a hand-crimped lead seal containing his “bug,” or identifying mark, which he attached with wire to items of evidence (Figure 5). This would allow him to identify the item during his testimony in court. The authors found this seal on a historic revolver held in a display case at the Larimer County Sheriff’s Office in Fort Collins, Colorado.

Figure 5—Pliers showing a lead evidence seal with the Tangen "bug".
(Photo courtesy Colorado Historical Society)

In addition to writing several articles, Tangen was also a member of the IAI from 1926 to 1952. He is listed in the 1932 edition of the Superintendents of Identification Bureaus of the World printed by the Institute of Applied Science. Aside from these few listings and articles, the authors have not been able to locate any other documentation showing Tangen’s correspondence with other examiners or attendance at annual conferences. We do know that he had access to a fairly large collection of forensic textbooks, but the exact titles remain a mystery.

Several items of Tangen’s personal property were acquired from his estate by the Boulder County Sheriff’s Office. Among these items are his prescription eyeglasses; the collection of .22 caliber rimfire cartridges; a Spencer Buffalo Comparison microscope (48mm 2.2x); custom photography submission envelopes; and his personal copy of The Classification of Fingerprints.

Like many photographers, Tangen employed the use of his bug or identifier in many of his prints. The Tangen bug was comprised of a capital letter “T” inside a diamond (Figure 6). The bug was typically placed in the lower right corner of the photograph. In his earlier years, Tangen also used the initials E.T. inside the diamond, although this bug was not seen in any of his crime-scene photographs. It is quite possible that some of Tangen’s photo-graphs currently reside in the collections of various crime laboratories, including the FBI.

Figure 6—This is Tangen's "bug" or copyright logo.
If you see it on any old photos, please notify the authors of this article.
(Photo courtesy of the authors)

The quality of work produced by Tangen is something to be admired. A self-taught criminalist, he set standards in his work that would be commendable in many laboratories today. To achieve that type of professionalism in a small community that certainly did not expect it is all the more impressive. Ed Tangen is a reminder that the accolades our profession enjoys today were built from the hard work of our predecessors. The contributions of many of these men and women have either been lost, forgotten, or are in danger of both. We must endeavor to celebrate their accomplishments and failures because it is by their work that our profession evolves. Like our own family trees, we may not realize what lessons have been passed down by which family members through the generations, but we owe it to the next generation to continue the cycle of learning.

Tangen was both a student and a teacher. That is the legacy of his work ethic. We must never stop learning, and we must never stop teaching.

Request for assistance

The authors of this article are searching for two bulletins that were self-published by Tangen during the 1930s or 1940s. Bulletins #3 and #4 have not been located and therefore, no title is available. The authors have been unable to locate any reference to these publications but their existence seems likely given the fact that bulletins #1, #2, #5, and #6 have been found. Tangen was known to share his writings with others, especially the FBI. These documents may be located in someone’s library and the authors would be indebted to anyone who could furnish a copy. We are also interested in obtaining copies of any crime-scene photographs taken by Tangen. The Tangen “bug” may be visible in some of these photographs.


The authors are indebted to Tom Meier for his outstanding research into the life of Ed Tangen; to Eric Paddock of the Colorado Historical Society whose relentless pursuit of the Tangen negatives saved valuable and irreplaceable documents for our profession and to his staff for their patience and assistance in our search; to Ted Ritter of the Denver Police Department Firearms Lab for his insight and review of the Tangen publications; to Silvia Pettem for her vast knowledge of Boulder County history; to Lt. Joseph Gang of the Boulder County Sheriff’s Office for allowing us to view the Tangen artifacts in his office; to the staff at the Denver Public Library Western History Department who were always available and helpful in our research; to Norman Smith, historian for the IAI; and finally to Dock Teegarden for unconditionally accepting us as law-enforcement colleagues and enthusiastically sharing his rare first-hand recollections and insights, which were truly invaluable to our research.

About the Authors

Thomas W. Adair is a senior criminalist with the Westminster (Colorado) Police Department. Bruce Adams is a criminalist with the Littleton (Colorado) Police Department. The authors can be reached via Adair’s e-mail address: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

"Historic Perspective: A Forensic Pioneer in Colorado," written by Thomas W. Adair and Bruce Adams
July-August 2008 (Volume 6, Number 4)
Evidence Technology Magazine
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