100 Fun Facts About Fingerprints

What are the three basic fingerprint patterns in the Henry system?

Loop, whorl and arch gave police a way to sort every set of prints into classes, so a clerk could track down one person's card among thousands without knowing a name.

A fingerprint left at the scene was one of the only clues when which Louvre painting was stolen in 1911?

Mona Lisa stayed missing for more than two years despite that print. The thief, a former Louvre workman, was caught only when he offered the painting to an art dealer in Florence.

A loop that starts on the little-finger side of the finger is called what?

Ulnar loops are named for the ulna, the forearm bone that runs down the little-finger side of the arm. They are also the most common fingerprint pattern of all.

Why do identical twins have different fingerprints despite sharing the same DNA?

Each grew differently in the womb: tiny differences in pressure and timing while the skin forms shape every fingertip separately, which is why even one person's ten fingers never match.

What is the name for the raised skin that leaves a fingerprint?

Friction ridges also sharpen the sense of touch: as a fingertip strokes a surface they amplify the tiny vibrations, helping nerves deep in the skin to read fine textures.

What is a chance fingerprint that is invisible to the naked eye called?

A latent print is strictly one that nobody can see until powder or chemicals bring it out, though police tend to use the word loosely for any print found at a crime scene.

A Chicago jury convicted Thomas Jennings of murder in 1910 after he left fingerprints on a railing coated in what?

Fresh paint on a porch railing kept his prints, and police cut the rail away as evidence. When Illinois's top court upheld the verdict, it set the precedent for fingerprints in American trials.

Which glands secrete most of the watery residue left behind by a fingertip?

Eccrine glands open on the fingertips themselves, while the oily part of a print is borrowed: it rubs off on the fingers each time a hand touches the face or hair.

Which reagent turns amino acids in a fingerprint deep purple?

Ninhydrin was first made by accident in 1910 and soon betrayed the fingerprints of any chemist who handled a test paper, yet police did not take it up until 1954.

Fumes of which household glue are used to reveal prints on glass and plastic?

Superglue fumes react with the traces a fingertip leaves and harden into a white outline of the print. The same glue was sprayed on wounds in the Vietnam War to slow soldiers' bleeding until they reached hospital.

How are prints lifted from a nonporous surface after dusting with powder?

With transparent tape pressed over the dusted print, the powder pattern peels away whole. Paper soaks a print up instead, so it is treated with chemicals, not dusted.

What is the technique for recording fingerprints digitally on a glass plate called?

Live scan needs no ink or paper: the prints are captured electronically and sent straight to a central database, which checks them against its files automatically.

In which ancient city were fingerprints already being used to seal business contracts?

Babylon's traders pressed a fingertip into the wet clay of a tablet to seal a deal, many centuries before any scientist took an interest in the patterns.

Under which Chinese dynasty, more than 2,000 years ago, did investigators record handprints as evidence at burglary scenes?

Qin officials had a written guide to investigating burglaries that counted handprints at the scene as evidence. In the same era a document was sealed with clay bearing its author's fingerprint, as proof of who had sent it.

Which professor of anatomy at Bologna described the patterns on human fingertips in the 1680s?

Marcello Malpighi was among the first to turn the newly invented microscope on the human body, and a layer of the skin still carries his name.

Which anatomist, namesake of brain cells, named nine fingerprint patterns?

Jan Evangelista Purkyně gave each of the nine patterns a name and went no further: nowhere in his thesis did he suggest that fingerprints could tell one person from another.

Where did Sir William Herschel start using fingerprints on contracts in 1858?

Bengal, India, is where Herschel had a road contractor press his whole hand onto a deal, simply to scare the man out of ever denying his own signature.

Which Scottish surgeon working in Tokyo published the first paper on fingerprints for identification in 1880?

Henry Faulds grew curious after spotting finger marks on fragments of ancient Japanese pottery, and went on to suggest catching criminals by the prints they left behind.

A Scottish doctor's 1880 letter on fingerprints and crime appeared in which journal?

Nature ran the letter in October 1880. In it the doctor told how a greasy fingermark had already shown him who had been helping themselves to some spirits.

Which naturalist did a Scottish doctor in Tokyo ask to promote his fingerprint work?

Charles Darwin, by then in his seventies, declined to take it up himself, but he did pass the letter on to a cousin who went on to study fingerprints.

Who published the statistical model of fingerprint identification in the 1892 book Finger Prints?

Francis Galton took up fingerprints hoping they would reveal a person's character and ancestry. He found they showed neither, only that no two were alike.

Which Argentine police officer created the first system for filing individuals' fingerprints in 1892?

His system was adopted across South America.

Which kind of medical treatment can erase a patient's fingerprints, as one traveller stopped at the US border found out?

Chemotherapy with one common drug can make the fingertips peel until the prints are gone. A Singapore man on it was held for hours by US immigration, and his doctor urged other patients to carry a letter.

What did Argentina become the first country to do after the Rojas case?

It abolished Bertillon's body-measurement system for identifying criminals.

Which Frenchman's anthropometry system, based on body measurements, did fingerprints replace?

Alphonse Bertillon's measurements were dropped within a few decades, but one part of his method outlived them: he standardised the mug shot, with its front and side views.

At which city's 1904 World's Fair did a Scotland Yard officer begin teaching American police to take fingerprints?

St. Louis had a Scotland Yard man, John Ferrier, on duty at the fair. He showed visiting police chiefs what fingerprints could do, then stayed on in America to teach the method.

In a famous 1903 story, fingerprints told apart two lookalike inmates, both named West, at which American prison?

Leavenworth's clerks are said to have found that the two Wests matched in face and body measurements, but not in their prints. Later research suggests the pair were probably related, perhaps even twins.

Who took charge in 1924 of the US government's new central file of more than 800,000 fingerprint cards?

J. Edgar Hoover merged two collections: the federal government's own cards and those America's police chiefs had gathered. The chiefs themselves had lobbied the Justice Department for a single national file.

Which post did Edward Henry hold from 1903 to 1918?

Commissioner of the Metropolitan Police was where the fingerprint system named after him took Henry, though two of his sub-inspectors, Azizul Haque and Hem Chandra Bose, are credited with working most of it out.

In 1912 a man shot fingerprint pioneer Edward Henry outside his London home after being refused a licence to do what?

Drive a taxi. Henry survived, asked the court to go easy on his attacker and, when the man came out of prison ten years later, paid his fare to a new life in Canada.

The Great Train Robbers of 1963 were caught partly through fingerprints left on which board game at their hideout?

Monopoly, which the gang had been playing with real banknotes from the haul. They wiped the farmhouse down before they fled but missed the board and a ketchup bottle.

In a robbed London paint shop, what bore Alfred Stratton's thumbprint?

A cash box. An inspector showed the jury, point by point, where the print on it matched Stratton's right thumb, in the first English murder trial to use fingerprints as evidence.

Who established the first forensic laboratory in France in 1910?

Edmond Locard talked the Lyon police into lending him two attic rooms and two assistants. From there he gave forensic science its founding rule: every contact leaves a trace.

Which American lawyer was wrongly held by the FBI in 2004 over a faulty print match?

Brandon Mayfield, an Oregon lawyer, was arrested after FBI examiners matched him to a partial print from the Madrid train bombings. Spanish police traced it to another man, and the FBI apologised in public.

Scottish detective Shirley McKie was wrongly accused of leaving her print where?

On a door frame at a murder scene, inside a house she insisted she had never entered. Charged with lying on oath, she was cleared in 1999, and a public inquiry later confirmed the print was not hers.

In which 1997 film does a new recruit have his fingerprints erased?

Men in Black strips its agents of any identity. While the recruit's prints are being removed, his new partner sits at a computer deleting his identity records one by one.

Which Apple phone introduced the Touch ID sensor in 2013?

The 5s hid the fingerprint reader in its home button. Four years later Apple began dropping both from its top phones in favour of face recognition.

Where does Apple store Touch ID fingerprint data?

In a secure enclave on the chip, and not as a picture: the phone keeps only a mathematical summary of each print, from which Apple says the finger's image cannot be rebuilt.

Which animal's fingerprints are hard to tell from a human's, even under a microscope?

Koala prints evolved quite separately from ours: the koala's closest relative, the wombat, has none at all. The likeness is a case of evolution arriving at the same design twice.

What is the rare condition of being born without fingerprints called?

Adermatoglyphia earned the nickname 'immigration delay disease' after a Swiss woman who had it was held up at the US border, where visitors are fingerprinted on arrival.

A 2009 University of Manchester study challenged the long-held belief that fingerprints evolved to improve what?

Our grip on objects. Pressed against sheets of acrylic, a fingertip's grooved skin touched a third less of the smooth surface than flat skin would have, so it held on no better.

Which Mark Twain novel turns on a courtroom fingerprint identification?

Pudd'nhead Wilson's lawyer hero collects his neighbours' fingerprints as a hobby, then uses the collection in court to unmask a murderer. Twain had already used a thumbprint clue in Life on the Mississippi.

In 2024, what did a Columbia University AI find about the prints on one person's different fingers?

They resemble one another. Examiners had treated each finger as unmatchable to its neighbours, but the AI ignored the fine details they compare and looked at the sweep of the lines at a print's centre.

Which company sold a smartphone with a fingerprint reader, the Atrix, two years before Apple's Touch ID arrived?

Motorola built the Atrix's reader into the power button on the back of the phone, so one button both woke the handset and checked who was holding it. One reviewer called the spot a bit awkward.

New York began America's first systematic fingerprinting in 1902 to stop impostors from doing what?

Sitting civil service exams. Candidates gave their prints when they applied, again at every test and once more on their first day at work, so a clever stand-in could not take the papers for them.

British chemists showed in 2007 that the sweat in a single fingerprint can reveal whether its owner does what?

Smokes tobacco. The test looks for cotinine, which the body makes only after taking in nicotine, so merely handling a cigarette will not trigger it and washing the hands will not hide it.

The Aadhaar identity scheme, which covers more than a billion people, records ten fingerprints, a photograph and a scan of what?

Both irises. The extra scan lets the scheme recognise people whose fingerprints are hard to read, among them young children and the elderly, whose prints scanners often struggle to capture.

Which 2017 iPhone was the first to drop the Touch ID fingerprint sensor in favour of face recognition?

iPhone X had nowhere left to put the sensor: its screen ran from edge to edge and the home button was gone, so Apple switched to a camera that maps the owner's face.

Which Sherlock Holmes story of 1903 turns on the discovery of a bloody fingerprint?

The Norwood Builder turns the clue on its head: the bloody thumbprint is a forgery, pressed onto the wall from a wax seal, and Holmes knows it because the mark was not there the day before.

Which word, built from the Greek for 'finger' and 'to look at', is the technical name for fingerprint identification?

Dactyloscopy shares its first half with the pterodactyl, whose name means 'wing finger': each of the animal's wings was stretched from a single, enormously lengthened finger.

Whose hands were cut off after his 1967 execution in Bolivia so fingerprints could prove his identity?

Che Guevara's hands were removed by a military doctor and kept as fingerprint proof of who he was, while the rest of his body lay in a secret grave for 30 years.

A Japanese cryptographer fooled eleven fingerprint readers with fake fingers moulded from which kitchen ingredient?

Gelatin from the grocery store, the stuff of gummy sweets, made fake fingers that fooled the sensors about 80% of the time, for roughly $10 in supplies.

Which 1930s bank robber burned his fingertips with acid, yet left fingerprints that still matched his old records?

John Dillinger had his fingertips treated in 1934, but prints taken after he was shot dead that summer still matched those from an earlier arrest almost completely.

Which mathematician proposed the stripe-forming chemical process that a 2023 study found also shapes fingerprints?

Alan Turing proposed in 1952 that two interacting chemicals could spread and produce spots and stripes, and the 2023 work found the ridges of a fingertip obey the same rules.

In 2014 a hacker cloned German defence minister Ursula von der Leyen's fingerprint using nothing more than what?

Standard camera pictures were enough: shots of her hands were fed into off-the-shelf software, which rebuilt the print.

Which 1989 science-fiction sequel imagined people in 2015 paying for things by thumbprint?

Back to the Future Part II also showed tablets that read fingerprints, and by the real 2015 phone payments secured by a fingerprint had just arrived.

A 2004 study of the Venus of Dolní Věstonice, a prehistoric ceramic figurine, found a fingerprint left by whom?

A child of between seven and fifteen touched the clay before it was fired, though researchers doubt anyone so young actually sculpted the figure.

Burglars who wear thin gloves made of which material may still leave their own fingerprints on what they touch?

Latex clings so thinly and tightly that the ridges of the fingers can press straight through it, transferring the wearer's prints to whatever is handled.

Which serial killer was named in 1985 when California's new fingerprint computer matched a print from a stolen car?

Richard Ramirez, the Night Stalker, was matched from one print on the car's mirror; the system held only people born from 1960 on, and he was born that February.

Fingerprints on a dropped rifle led the FBI to which escaped convict after Martin Luther King Jr.'s murder?

James Earl Ray had broken out of a Missouri prison a year earlier by hiding in a bread truck, and later claimed he left the rifle in plain sight because he wanted to be a famous criminal.

Which print do hospital staff usually record from a newborn baby, rather than taking fingerprints?

Footprints are the usual hospital record for a newborn, so when an unknown infant has to be identified, examiners take prints from the feet to compare.

The ridged skin that makes fingerprints is unusual because it completely lacks which common feature of human skin?

Hair never grows on the ridged skin of the fingers and soles, and nor do oil glands, which is why the greasy part of a fingerprint comes mostly from touching the forehead.

Fingerprint ridges sharpen the sense of fine texture by amplifying what as a fingertip brushes over a surface?

Vibrations triggered as a fingertip crosses an uneven surface are amplified by the ridges, so clearer signals reach the nerves that judge how rough or smooth it is.

Silver nitrate reveals fingerprints on paper by reacting with which everyday compound left behind in sweat?

Salt in the residue reacts to form silver chloride, which light slowly turns to dark silver, though the image blurs with time as the chloride spreads through the paper.

The classic black dust that American examiners brush over fingerprints on light surfaces is based on which element?

Carbon black, a fine soot-like pigment, is among the most common fingerprint dusts because its dark grey image shows up on surfaces of many colours.

Which type of fingerprint reader works by sending pulses through the outer layer of the skin?

Ultrasonic readers fire high-frequency sound waves that pass through the epidermis, the same principle hospitals use to image the body.

In AFIS, the computer system police use to search fingerprints against millions of records, what does the A stand for?

Automated is the point: the computer suggests likely candidates in moments, and a technician usually confirms the match by eye.

America's last stagecoach robbery, in Nevada in 1916, was solved by a bloody print of what on an envelope?

A palm print in blood tied Ben Kuhl to the rifled mail sacks, making him the first American murderer convicted on that kind of evidence.

In 1902 Harry Jackson became the first person in Britain convicted on fingerprint evidence, after stealing what?

Billiard balls were the haul from a house in Denmark Hill, where a thumbprint on the windowsill matched the file of Jackson, a labourer just out of prison for burglary.

In dated British slang, which short word for fingerprints do police take from a suspect at the station?

Dabs is used chiefly in the plural, as in having your dabs taken, and a Scottish crime novel was using the slang as late as 2022.

Paul-Jean Coulier pioneered capturing fingerprints on paper by fuming with which element, named for its violet vapour?

Iodine fuming works best on fairly recent prints, while some other reagents have brought up marks that were decades old.

Hundreds of British schools began reading pupils' fingerprints in the early 2000s, at first as a replacement for what?

Library cards went first: one supplier counted 350 schools using its fingerprint system in 2002, and within five years the estimate had grown tenfold.

ACE-V is the method fingerprint examiners follow: analysis, comparison, evaluation and which final step?

Verification means a second examiner independently repeats the analysis, comparison and evaluation to support or refute the first examiner's conclusion.

Amido black, a dye used on fingerprints left in blood, works by staining which component of the blood?

Proteins of any kind take up the dye, darkening a faint bloody mark, and it is typically used to bring up bloody impressions left on human skin.

Vacuum metal deposition reveals fingerprints on polythene bags by coating them with zinc after a trace of which metal?

Gold goes on first because zinc settles only where specks of metal sit at the surface; the gold sinks into the greasy ridges, so they stay bare while the background is coated.

Which light source did Xerox researchers in Canada first use in 1976 to make untreated fingerprints glow on their own?

A laser, an argon ion model, made traces in the residue such as riboflavin fluoresce faintly, and soon afterwards the method identified a print in a real criminal case.

Forensic scientists use the term plastic print for a fingerprint that has which special property?

Three-dimensional prints are pressed into soft surfaces such as soap, wax or caulk, and unlike most marks they can be seen with the unaided eye.

Besides identification and exclusion, what third finding can a fingerprint examiner report when the detail is too poor?

Inconclusive results come from poor-quality marks, too little comparable area or too few matching or differing features for the examiner to be certain either way.

What do examiners call known fingerprints deliberately taken from a person, rather than marks found at a scene?

Exemplars taken at arrest normally include every finger rolled in ink, plus flat impressions of the four fingers of each hand pressed down together.

When police ink a suspect's fingers for a ten-print form, how far is each one rolled?

Nail edge to nail edge captures the whole pattern, and the flat prints of four fingers taken underneath then show that no finger was rolled in the wrong box.

Which force holds the dust on the bristle-free wand that examiners use to develop fragile fingerprints gently?

Magnetism lets the wand pick up a clump of iron-laced dust that acts as its own brush, far softer on a delicate mark than ordinary bristles.

Which country's MyKad was the first identity card to combine a photo with fingerprint data on a built-in microchip?

Malaysia introduced the card in 2001, and it was designed to open unmanned border gates that check the holder's fingerprint.

Which country fitted its electronic voting machines with fingerprint readers that check each voter before the ballot?

Brazil added a reader that checks the voter's fingerprint before the ballot can be cast, and 22 million voters were identified that way in the 2014 general election.

What name do examiners give a complete inked record of every ridged surface of both hands, taken in serious inquiries?

Major case prints go beyond the fingertips to the sides, lower joints and tips of every finger, because a mark left at a scene can come from any part of the hand.

Fingerprints on 1,000-year-old Puebloan pottery, measured by ridge width in a 2019 study, showed it was made by whom?

Both men and women shaped the pots, overturning the long-held assumption that Puebloan pottery was women's work; ridge breadth differs measurably between the sexes.

Which kitchen staple is blended into some fingerprint dusts to help the coloured particles cling to a print's residue?

Cornstarch is one of the binders that make a dust stick, alongside stearic acid and the spores of clubmoss, while a separate pigment supplies the colour.

Fingerprint officers in the United Kingdom are known for dusting with fine flakes of which silvery metal?

Aluminium flake shows up on a wide variety of surfaces, which made it the favourite in the United Kingdom, whereas American examiners more often reach for a dark granular dust.

Which American artist remade his portrait of composer Philip Glass in 1978 using only ink and his own fingerprints?

Chuck Close kept returning to the same image of Glass, also rendering it in watercolour and in handmade paper, to force himself into ways of working he had never tried.

Fingerprints grow back unchanged after a graze because the template for the ridges sits in which part of the epidermis?

The basal layer at the foot of the epidermis keeps sending up new cells in the same pattern, so only a wound deep enough to disrupt it leaves a permanent scar.

The FBI division that keeps America's national fingerprint files is based at Clarksburg, in which state?

West Virginia is home to the FBI's Criminal Justice Information Services Division, whose national fingerprint database went fully operational there in July 1999.

Which European Union database, running since 2003, stores asylum seekers' fingerprints to spot repeat claims?

Eurodac lets one country check whether an asylum seeker has already applied in another member state, which helps settle which state must handle the claim.

Which temporary swellings on a fetus's fingertips shape the pattern of the fingerprints that form over them?

Volar pads appear at around seven weeks and flatten out as the ridges form, and how lopsided each pad is at that moment steers the pattern that results.

After a 1948 hospital murder, police took fingerprints from over 40,000 local males in which Lancashire town?

Blackburn's adult males were printed house by house, on a promise that the records would be destroyed afterwards, and the match came with fewer than 200 sets left to check.

Which author introduced the forensic detective Dr Thorndyke in The Red Thumb Mark, a 1907 novel built on a fingerprint?

R. Austin Freeman went on to pioneer the inverted detective story, in which the reader knows who the criminal is from the very beginning.

Hermann Welcker began the first study of whether fingerprints last for life in 1856 by printing whose hand?

His own right hand was printed in 1856 and again in 1897, forty-one years apart, yet in the paper he finally published Welcker claimed no credit for the idea.

Which Japanese firm built the fingerprint computer that multiplied San Francisco's print matches tenfold in 1984?

NEC won the contract after head-to-head tests against rival systems, and the publicity around the city's results set off a rush of other police forces buying their own.

Which English wood engraver, famed for his bird books, published his own fingerprint as a personal mark?

Thomas Bewick engraved the print into three woodcuts between 1809 and 1826, though nobody knows whether he grasped that such a mark could identify a person.

In the TV western Bonanza, which member of the Ponderosa household uses fingerprints to clear Little Joe of murder?

Hop Sing, the Cartwrights' cook played by Victor Sen Yung, uses his knowledge of fingerprints in the 1968 episode Mark of Guilt to free Joe from the charge.

Which German hacker group published interior minister Wolfgang Schäuble's fingerprint in its magazine in 2008?

Chaos Computer Club went further than printing the image: the magazine carried the fingerprint on a thin film that readers could wear to fool fingerprint readers.

Ancient fingerprints survive on Minoan and Greek pottery and on the tomb walls of which other civilisation?

Egyptian tombs are among several ancient sites where workers and craftsmen left prints behind, alongside clay tablets, seals and Chinese pottery.