50 Fun Facts About Fingerprints

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

Loops are by far the most common of the three.

Roughly what share of all fingerprints are arches?

Loops are the most common, at 60 to 65 percent.

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

Radial loops start on the thumb side, near the radius bone.

Do identical twins have identical fingerprints?

Ridge formation is randomised in the womb, so even shared DNA does not produce matching prints.

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

They occur on fingers, toes, palms and soles.

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

Patent prints are visible; plastic prints are pressed into soft material like soap or putty.

A fingerprint pressed into soap, cement or plaster is called what by forensic scientists?

Chocolate, paint or ink on the fingers leaves patent prints instead.

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

Sebaceous oils, mostly from the forehead, add the fatty component.

Which reagent turns amino acids in a fingerprint deep purple?

The colour is called Ruhemann's purple after the chemist who discovered the compound in 1910.

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

Cyanoacrylate vapour polymerises on the ridges, leaving a white deposit.

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

Porous surfaces such as paper need chemical methods instead.

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

Ink rolled onto a white card is the traditional alternative.

Around 200 BCE, fingerprints were used to sign contracts in which ancient city?

Records from Hammurabi's reign suggest officials also took the prints of arrested people.

Under which Chinese dynasty did officials collect hand and foot prints as crime-scene evidence?

Chinese officials also authenticated documents with fingerprints.

Which Bologna anatomist identified ridges, spirals and loops in fingerprints in 1686?

A layer of the skin is still named after him.

Who identified nine fingerprint patterns in 1823?

German anatomist Johann Mayer had concluded in 1788 that prints were unique to each person.

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

He later registered pensioners' prints so relatives could not keep collecting after a death.

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

He proposed recording them with printing ink; Scotland Yard dismissed the idea in 1886.

In which journal did Faulds publish his 1880 fingerprint paper?

He offered the idea to the Metropolitan Police on returning to Britain in 1886 and was dismissed.

Which naturalist did Faulds ask for help promoting fingerprint identification?

Darwin declined but forwarded the idea to his half-cousin Galton.

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

He was Darwin's half-cousin and the coiner of the word eugenics.

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

His system was adopted across South America.

Which Argentine woman was the first person convicted of murder on fingerprint evidence?

A bloody thumb mark on a door matched her right thumb; she had blamed a neighbour.

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?

His flawed handwriting testimony also helped convict Alfred Dreyfus.

Which two Bengal sub-inspectors helped Edward Henry devise his classification system?

Their work between 1896 and 1897 let records be sorted and searched with ease.

How many groups does the Henry system's primary classification divide print sets into?

The fraction's numerator and denominator each run from 1 to 32.

In which year did Scotland Yard begin fingerprinting individuals to identify criminals?

Edward Henry, later Commissioner, brought his system from Bengal.

Which post did Edward Henry hold from 1903 to 1918?

He had been Inspector-General of Police of Bengal from 1891.

Where were the prints found that convicted the murderer Scheffer in 1902, the first such case?

The theft was in a dentist's apartment where an employee lay dead; Bertillon made the match.

The Stratton brothers, hanged in 1905, were the first Britons convicted of murder on fingerprint evidence; where was the crime?

The right thumbprint of Alfred Stratton was found on the Farrows' cash box.

On what object was Alfred Stratton's thumbprint found?

Detective Inspector Charles Collins concluded it matched his right thumb exactly.

Who established the first forensic laboratory in France in 1910?

He is remembered for the exchange principle: every contact leaves a trace.

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

He was linked to the Madrid train bombings and released with a public apology after two weeks.

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

She was sacked, arrested and acquitted in 1999; a public inquiry followed.

What does the FBI's IAFIS database name stand for?

It holds records of more than 51 million criminal subjects.

Which Apple phone introduced the Touch ID sensor in 2013?

German hackers bypassed it within days using a photographed print.

Where does Apple store Touch ID fingerprint data?

The design keeps the data off the cloud and away from attackers.

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

Climbing and grasping animals, including gorillas and the North American fisher, evolved prints too.

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

It was nicknamed immigration delay disease after a patient struggled to enter the US.

Faulty expression of which protein causes the no-fingerprints condition, per a 2011 study?

Affected patients also have flat finger pads and fewer sweat glands.

Which Mark Twain novel of 1893 turns on a courtroom fingerprint identification?

Twain had already discussed fingerprints in Life on the Mississippi ten years earlier.

What did a 2024 deep-learning study find about prints from different fingers of one individual?

The finding contradicted the prevailing assumption that each finger's print was independent.

The first professional certification for print examiners was set up in 1977 by which body?

The International Association for Identification could also revoke certificates.

A gene on chromosome 3, ADAMTS9-AS2, has been linked to which pattern on all digits?

How its variants shape whorl development has not yet been explained.

Whose iodine-fuming method let Scotland Yard start fingerprinting criminals in 1901?

American police departments soon adopted the same method and fingerprint identification became standard in the United States.

Which Iranian physician wrote that 'no two individuals have fingers exactly alike'?

He was describing the Chinese practice of identifying people by their fingerprints in the Jami al-Tawarikh.

After whose 1840 murder did a doctor urge Scotland Yard to check for fingerprints?

Herschel began fingerprinting in India in 1858 and by 1877 was using prints on contracts to prevent repudiated signatures.

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

Conan Doyle set the story in 1894, keeping his detective in step with real-life forensic developments.

Which aquatic North American mammal has evolved its own unique prints, like koalas and apes?

Such prints tend to evolve in animals whose lifestyle involves climbing or grasping wet objects.