It’s always freaky when several of my interests collide. Crime, old-time radio, and classic movies–it all comes together in this photo of the FBI photographing Margaret O’Brien.

“The 91 million prints we have on file here at the FBI are the biggest man trap ever devised.”

Adventure Ahead, August 26, 1944

This is not a great radio show. In my experience, the cheese factor in old-time radio correlates directly with the number of organ flourishes a show contains. But this show’s subject–how the FBI lab helped police solve crimes in the 1940s–intrigues me.

Adventure Ahead was a Saturday morning show aimed at young boys. In this episode, a boy tours the FBI crime lab and learns how agents help solve crimes through blood and hair analysis, ballistics, and fingerprint identification.

(This show uses what TV Tropes calls the Little Jimmy trope: “Little Jimmy is a young character without any distinguishable traits other than complete ignorance related to the subject at hand. Most likely found in educational films, commercials, and public service announcements. Their only job is to represent the young and stupid viewers of the film who know nothing about common sense and would very well get into a car with a stranger offering candy unless some superhero or other fictional character comes along and tells them that it’s wrong. He’s typically young, white and freckled.” Here, our Little Jimmy is named Tommy.)

Because I live near America’s largest fingerprint database, I paid special attention to the information about FBI fingerprint files. After listening to the show, I couldn’t resist doing some research on the history of fingerprint identification and how the FBI collection has changed over the years.

Soon after J. Edgar Hoover became FBI director in 1924, the Bureau established an Identification Division.
Within nine years, it contained 5 million cards. By 1944, when this radio show aired, these numbers had soared to 91 million. Actress Margaret O’Brien provided the Bureau’s 100 millionth set of fingerprints two years later.

This radio show describes a fingerprint matching system that involved punched cards and “steel fingers.” The FBI first used computers to search fingerprint files in 1980, but didn’t establish a fully computerized system, the Integrated Automated Fingerprint Identification System, until 1999.

The FBI is now building a huge database of other biometric information, from iris scans to tattoos.