Crime Library: Criminal Minds and Methods

All about Fingerprints and Other Impressions

The Persistence of Prints

During the Depression years when banks were foreclosing on the homes and farms of people at a record level, Americans tended to glamorize bank robbers as contemporary Robin Hoods. They followed the exploits of these criminals as if reading a serialized thriller, cheering for them and criticizing the police.

J. Edgar Hoover (CORBIS)
J. Edgar Hoover (CORBIS)

The FBI's J. Edgar Hoover was outraged by the grandiose attacks in the mid-1930s on Chicago-area banks by John Dillinger and his gang, but until they crossed state lines, his hands were tied. Dillinger's audacious (and highly profitable) spree inspired Hoover to dub him "public enemy number one."

Arrested once and heavily guarded in an "escape-proof" prison, he used a fake gun to escape. Then he crossed the state line into Indiana and went into hiding. The FBI closed in and Dillinger started to get nervous. A few of the agents assigned to the Dillinger squad were real bulldogs.

Knowing that the corpses of other criminals were being identified by prints, and that prints left at a crime scene could incriminate him, he came up with a plan. He located a team of plastic surgeons who also had criminal records and paid them $5000 to alter his facial appearance and burn off his fingerprints with acid. He nearly died under the botched anesthesia, but finally the operation was finished. His fingerprints were gone...or so he thought.

Dillinger WANTED poster
Dillinger "WANTED" poster

Still, it seemed that people recognized him and the owner of a bordello, the notorious "lady in red," set him up in exchange for reward money. She alerted the FBI about his planned movements for the evening of July 27, 1934, saying he would be in attendance at a certain theater. Agents covered two possible locations and waited for the notorious criminal to exit. Eventually they spotted him at the Biograph Theater in the company of two women.

As Dillinger walked out, the FBI agents closed in and ordered him to put up his hands and surrender. They claimed that he reached for something so they gunned him down. He ended up with four wounds, including the one that killed him: a bullet had entered his neck, traveled upward, and exited his right eye.

Almost immediately, people came forward to collect souvenirs. Women dipped handkerchiefs in his blood. Even as a dead man, Dillinger was still revered as a celebrity.

Taken to the morgue, he was thoroughly examined (and also subjected to a long line of curious onlookers who filed through). The FBI agents took his fingerprints and discovered the ploy. However, the doctors hadn't done their job. Around the acid-burned area a sufficient number of ridge patterns remained to identify the famous bank robber.

In fact, people who have tried to burn or cut away the tips of their fingers to remove the telltale prints have found that they grow back, and they take on exactly the same pattern they had before. The patterns also go down through several layers of skin. Even if an attempt to distort them succeeds, the distortion itself becomes part of the pattern, which means there's no real way to elude the fingerprint experts.

Let's look at what these experts do.


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