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15 Unique Facts About Fingerprints

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They've been with you since before you were born, but how much do you really know about the lines and ridges on your fingers, palms, and feet?

1. THEY’RE THE RESULT OF A STRUGGLE.

Human skin has several layers, and each layer has sub-layers. A developing fetus is constantly straining and stretching these layers, which can snag on each other. Scientists believe fingerprints form when the bottom layer of the epidermis grows at a different rate than the rest of the skin, causing it to buckle and tug on the dermis. Your fingerprints are made up of several skin layers twisted together [PDF], kind of like a soft-serve swirl.

2. BEFORE FINGERPRINTS, THERE WERE BONE MEASUREMENTS.

Image Credit: Jebulon via WikimediaCommons // CC0 BY 1.0

Alphonse Bertillon was a French policeman and researcher who capitalized on the fact that each person’s body proportions are different. He developed a way of using photographs to measure a person’s unique dimensions—a technique that’s still reflected in jailhouse mug shots. The Bertillon System, as it came to be known, was adopted by law enforcement agencies in Europe and North America and used for three decades. 

3. SOME PEOPLE ARE BORN WITHOUT THEM.

Three genetic conditions can prevent fingerprints from forming: Naegeli-Franceschetti-Jadassohn syndrome (NFJS), Dermatopathia pigmentosa reticularis (DPR), and adermatoglyphia. NFJS and DPR cause a range of symptoms, most much worse than smooth fingers. Adermatoglyphia, on the other hand, has just one indicator: no fingerprints. It’s sometimes referred to as “immigration delay disease,” for the trouble it causes people trying to cross borders. 

4. THEY KILLED THE BERTILLON SYSTEM.

In 1901, a man named William West began a life sentence in the Leavenworth, Kansas, penitentiary for murder. His Bertillon measurements were taken and dutifully cataloged. Two years later, Will West entered Leavenworth. When asked if he’d been there before, he said no, but the clerk took his measurements and photograph and found that they were an exact match for the man listed as William West who was currently in the prison. Befuddled, the clerk compared Will’s fingerprints with William's and found that, indeed, they were two completely different men. The story is still a matter of debate—some think the men might have been twins—but it soon became folklore among forensic scientists, illustrating not only the advantages of fingerprinting but the fatal flaws that would lead to the abandonment of the Bertillon system.

5. FINGERPRINT ANALYSIS IS FALLIBLE.

Image Credit: Daekow via Wikimedia Commons // CC BY-SA 4.0

When examining fingerprints, experts attempt to match as many points of comparison as possible, but there’s no minimum for a match, at least not in the United States. Other countries have set standards for what constitutes a positive identification, but not us. On top of that, there’s an inevitable element of human error. A 2011 study [PDF] found a false positive rate of 0.1 percent. That may not sound like much until you realize that 0.1 percent of the FBI’s annual fingerprint intake is 60,000 people, or 60,000 potential false positive IDs.

6. KOALAS HAVE THEM, TOO.

Image Credit: Mike R via Wikimedia Commons // CC BY-SA 3.0

So far, we’re aware of only a few non-human animals with unique fingerprints, such as gorillas, chimpanzees, and koalas. Given apes’ and koalas’ arboreal lifestyles, scientists suspect fingerprints evolved as a consequence of living in trees. The fingerprints of koalas are so similar to humans’ that even experts have trouble telling them apart. We haven’t heard of anyone blaming their misdeeds on a koala yet, but it’s probably just a matter of time. 

7. FINGERPRINTS ARE INCREDIBLY DURABLE …

Image Credit: Zephyris via Wikimedia Commons // CC BY-SA 3.0

Even in death, our fingerprints stick around, which makes them very helpful in identifying bodies. Or fingers, in the case of Hans Galassi. After losing a few fingers in an accident on the water, the wakeboarder figured they were gone for good. Then a human finger turned up in the belly of a trout and, sure enough, it was one of Galassi’s. “If a hand is found in water you will see that the epidermis starts to come away from the dermis like a glove,” fingerprint expert Allen Bayle told the BBC. “This sounds gruesome, but if a hand has been badly damaged, I cut the epidermis off and put my own hand inside that glove and try to fingerprint it like that.” (Once the severed finger had been identified, it was offered to Mr. Galassi, who declined to take it back.)

8. … BUT YOU CAN LOSE THEM …

Rough tactile work like bricklaying and chemotherapy drugs like capecitabine can erode and even erase fingerprints. “Just a good case of poison ivy would do it," forensics expert Edward Richards said in Scientific American. Don’t get too worried: "Left alone,” he said, “your skin replaces at a fairly good rate, so unless you've done permanent damage to the tissue, it will regenerate." 

9. … ESPECIALLY IF YOU’RE DETERMINED.

By the 1930s, fingerprint analysis was standard practice in U.S. law enforcement, and criminals had begun intentionally trying to remove their fingerprints. As you might imagine, the results were grisly and mixed. Some tried to file off their prints, while others attempted to cut them out. Notorious gangster John Dillinger burnt his own prints off with acid, a hardcore decision that kind of worked. (His fingerprints were never used against him, but after his death the faint traces of his former ridges and whorls could still be seen.) Robber Robert Phillips talked a doctor into grafting skin from his chest onto his fingertips. Unfortunately for him, he neglected to remove the prints on his palms. 

10. FINGERPRINT SENSORS MIGHT WORK FOR YOUR PETS, TOO.

Image Credit: cloudzilla via Wikimedia Commons // CC BY 2.0

Apple created quite a buzz in 2013 when it introduced a fingerprint-coded screen lock with the iPhone 5s. Some of that buzz soon focused on cats, however, after a TechCrunch writer “commandeer[ed] a cat” and used its toe pad to create a new profile. “The cat’s paw worked,” he wrote, “and while it encountered more frequent failures than did a fingerprint, it was able to unlock the phone again repeatedly when positioned correctly on the sensor.”

11. MARK TWAIN ANTICIPATED THE VALUE OF FINGERPRINT EVIDENCE.

Two of the author’s books, Life on the Mississippi and Pudd’n Head Wilson, feature the use of fingerprints to nab criminals. Twain’s focus on fingerprinting was incredibly prescient; the books were published in 1883 and 1893, respectively, but U.S. officials wouldn’t implement fingerprinting practices here until the early 20th century. 

12. WORLD WAR II SAW A BOOM IN FINGERPRINT COLLECTION.

Wartime vigilance meant that the FBI was collecting more prints than ever before, from soldiers, foreign agents, and military suppliers, as well as draft dodgers and potential spies. By 1943, the collection included more than 70 million prints. To manage the explosion of information, the agency moved to a big warehouse (nicknamed the “Fingerprint Factory”) and hired and trained thousands of women to sort prints 10 hours a day, six days a week. 

13. THERE HAVE BEEN SEVERAL CASES OF MASS FINGERPRINTING.

In desperate times, British police have resorted to desperate measures. The shocking murder of a three-year-old girl in 1948 inspired officials to demand prints from more than 40,000 local men. Even with all those prints, they failed to find a match—until they tracked down the 200 men who had failed to produce prints. Among them, they found their culprit. Since then, despite protestations from Britain’s National Council for Civil Liberties, the police have conducted several mass print collections, several of which were successful. 

That sort of thing doesn’t go over too well in the United States, but it has been done. The Fourth Amendment restricts the use of fingerprint collection to “reasonable” identification of persons of interest in criminal cases. Law enforcement officers could get around this if they chose, but it wouldn’t be a popular move.

14. THE FBI STORES EVERYBODY’S PRINTS TOGETHER.

If you’ve ever applied for a teaching job, the police force, or any government position, the FBI has your fingerprints—and they’re treating them like a criminal’s. In 2015, the agency announced that they were melding their criminal and civil fingerprint databases. They also decided to make all files searchable for potential culprits.

15. THE MICROBIOME IS THE NEW FINGERPRINT.

Like the whorls and loops of your fingerprints, the tiny ecosystems in and on your body are yours and yours alone. The collective DNA of the bacteria, fungi, and viruses that make up your microbiome is a huge repository of information about your health, environment, diet, and genetics—and it’s completely unique. Forensic scientists are currently exploring the possibility of using microbiomes for identification, and testimony based on microbial forensic techniques has already been admitted in some U.S. courts.

 

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10 Regional Twists on Trick-or-Treating
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Walk around any given American neighborhood on the night of October 31, and you’ll likely hear choruses of "trick-or-treat" chiming through the area. The sing-songy phrase is synonymous with Halloween in some parts of the world, but it's not the only way kids get sweets from their neighbors this time of year. From the Philippines to the American Midwest, here are some regional door-to-door traditions you may not have heard of.

1. PANGANGALULUWA // THE PHILIPPINES

Rice cakes wrapped in leaves.
Suman

The earliest form of trick-or-treating on Halloween can be traced back to Europe in the Middle Ages. Kids would don costumes and go door-to-door offering prayers for dead relatives in exchange for snacks called "soul cakes." When the cake was eaten, tradition held that a soul was ferried from purgatory into heaven. Souling has disappeared from Ireland and the UK, but a version of it lives on halfway across the world in the Philippines. During All Saints Day on November 1, Filipino children taking part in Pangangaluluwa will visit local houses and sing hymns for alms. The songs often relate to souls in purgatory, and carolers will play the part of the souls by asking for prayers. Kids are sometimes given rice cakes called suman, a callback to the soul cakes from centuries past.

2. PÃO-POR-DEUS // PORTUGAL

Raw dough.
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Instead of trick-or-treating, kids in Portugal go door-to-door saying pão-por-deus ("bread for god") in exchange for goodies on All Saints Day. Some homeowners give out money or candy, while others offer actual baked goods.

3. HALLOWEEN APPLES // WESTERN CANADA

Kids trick-or-treating.
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If they're not calling out "trick-or-treat" on their neighbors’ doorsteps on Halloween night, you may hear children in western Canada saying "Halloween apples!" The phrase is left over from a time when apples were a common Halloween treat and giving out loose items on the holiday wasn't considered taboo.

4. ST. MARTIN'S DAY // THE NETHERLANDS

The Dutch wait several days after Halloween to do their own take on trick-or-treating. On the night of November 11, St. Martin's Day, children in the Netherlands take to the streets with their homemade lanterns in hand. These lanterns were traditionally carved from beets or turnips, but today they’re most commonly made from paper. And the kids who partake don’t get away with shouting a few words at each home they visit—they’re expected to sing songs to receive their sugary rewards.

5. A PENNY FOR THE GUY // THE UK

Guy Fawkes Night celebration.

Peter Trimming, Wikimedia Commons // CC BY-SA 2.0

Guy Fawkes Night is seen by some as the English Protestants’ answer to the Catholic holidays associated with Halloween, so it makes sense that it has its own spin on trick-or-treating. November 5 marks the day of Guy Fawkes’s failed assassination attempt on King James as part of the Gunpowder Plot. To celebrate the occasion, children will tour the neighborhood asking for "a penny for the guy." Sometimes they’ll carry pictures of the would-be-assassin which are burned in the bonfires lit later at night.

6. TRICKS FOR TREATS // ST. LOUIS, MISSOURI

Kids knocking on a door in costume.
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If kids in the St. Louis area hope to go home with a full bag of candy on Halloween, they must be willing to tickle some funny bones. Saying "tricks-for-treats" followed by a joke replaces the classic trick-or-treat mantra in this Midwestern city. There’s no criteria for the quality or the subject of the joke, but spooky material (What’s a skeleton’s favorite instrument? The trombone!) earns brownie points.

7. ME DA PARA MI CALAVERITA // MEXICO

Sugar skulls with decoration.
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While Dia de los Muertos, or Day of the Dead, is completely separate from Halloween, the two holidays share a few things in common. Mexicans celebrate the day by dressing up, eating sweet treats, and in some parts of the country, going house-to-house. Children knocking on doors will say "me da para mi calaverita" or "give me money for my little skull," a reference to the decorated sugar skulls sold in markets at this time of year.

8. HALLOWEEN! // QUEBEC, CANADA

Kids dressed up for Halloween.
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Trick-or-treaters like to keep things simple in the Canadian province of Quebec. In place of the alliterative exclamation, they shout “Halloween!” at each home they visit. Adults local to the area might remember saying "la charité s’il-vous-plaît "(French for “charity, please”) when going door-to-door on Halloween, but this saying has largely fallen out of fashion.

9. SWEET OR SOUR // GERMANY

Little girl trick-or-treating.
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Halloween is only just beginning to gain popularity in Germany. Where it is celebrated, the holiday looks a lot like it does in America, but Germans have managed to inject some local character into their version of trick-or-treat. In exchange for candy, kids sometimes sing out "süß oder saures"—or "sweet and sour" in English.

10. TRIQUI, TRIQUI HALLOWEEN // COLOMBIA

Kids dressed up for Halloween.
Rubí Flórez, Flickr // CC BY-NC-ND 2.0

Kids in Colombia anticipate dressing up and prowling the streets on Halloween just as much as kids do in the States. There are a few significant variations on the annual tradition: Instead of visiting private residencies, they're more likely to ask for candy from store owners and the security guards of apartment buildings. And instead of saying trick-or-treat, they recite this Spanish rhyme:

Triqui triqui Halloween
Quiero dulces para mí
Si no hay dulces para mí
Se le crece la naríz

In short, it means that if the grownups don't give the kids the candy they're asking for, their noses will grow. Tricky, tricky indeed

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11 Thrilling Facts About Dial M for Murder
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In 1953 Alfred Hitchcock was looking for a new project after a film he’d been developing fell through. Sensing a need to go back to his safe space of murderous thrillers, he opted to adapt a stage play that had already proved to be a hit on British television. Though he had no particular attachment to the project, Dial M for Murder would ultimately become one of Hitchcock’s best-known—and best-loved—classics.

From the film’s use of 3D to the debut of Grace Kelly in Hitchcock’s filmography to a pivotal murder sequence that made the director lose weight from stress, here are 11 facts about Dial M for Murder.

1. IT’S BASED ON A STAGE PLAY.

Dial M for Murder is, in terms of locations and number of characters, a relatively sparse film that barely leaves its primary set. This is because it was based on a stage play by Frederick Knott, which premiered as a BBC TV special in 1952 and later opened at London’s Westminster Theater and, eventually, Broadway. After seeing the BBC production, producer Sir Alexander Korda purchased the rights to make the film version, and later sold them to Warner Bros. for $75,000.

2. ALFRED HITCHCOCK THOUGHT HE WAS “COASTING” WHEN HE MADE THE FILM.

By 1953, when Dial M for Murder arrived at Warner Bros., Hitchcock was developing a project called The Bramble Bush, the story of a man who steals another man’s passport, only to find out that the original owner is wanted for murder. Hitchcock wrestled with the story for a while, but was never satisfied with it. When Dial M for Murder landed at the studio, Hitchcock knew the play had been a hit, and opted to direct it. As he later told fellow director François Truffaut, he found the film to be “coasting, playing it safe,” as he was already known as a thriller filmmaker.

3. IT’S HITCHCOCK’S ONLY 3D FILM.

In the early 1950s, the 3D movie craze was raging, and Warner Bros. was eager to pair it with the fame of Hitchcock. So, the director was ordered to use the process on Dial M for Murder. This meant Hitchcock had to work with the giant cameras necessary for the process, but there was also a trade-off that makes the film fascinating—even in 2D. In order to make the film look appropriately interesting in 3D, Hitchcock added a pit into the floor of the set, so the camera could move at lower angles and captures objects like lamps in the foreground. As a result, the film looks like no other Hitchcock ever shot, particularly for the infamous scissors murder that’s the film's thrilling centerpiece. Unfortunately, by the time Dial M for Murder was released in 1954, the 3D fad was dying out, so the film was shown in 2D at most screenings.

4. IT WAS HITCHCOCK’S FIRST FILM WITH GRACE KELLY.

Of all of the iconic blonde stars Hitchcock cast in his films, the most famous is almost undoubtedly Grace Kelly, the actress-turned-princess who first joined him for this film. Hitchcock once described Kelly as a "rare thing in movies ... fit for any leading-lady part,” and it was said he had the easiest working relationship with her of any star. They worked so well together that they went on to make two more films, Rear Window in 1954 and To Catch a Thief in 1955.

5. IT TAKES PLACE ALMOST ENTIRELY INDOORS.

Because Dial M for Murder is based on a stage play, the original script had very little in the way of outdoor set pieces. Hitchcock wanted to keep it that way, as he later explained to Truffaut:

“I’ve got a theory on the way they make pictures based on stage plays; they did it with silent pictures, too. Many filmmakers would take a stage play and say, ‘I’m going to make this into a film.’ Then they would begin to ‘open it up.’ In other words, on the stage it was all confined to one set, and the idea was to do something that would take it away from the confined stage setting.”

Hitchcock wanted to keep the confinement intact, so almost all of the action in the film takes place indoors, largely in the Wendices' apartment. This adds to the intimacy and tension.

6. HITCHCOCK PERSONALLY CHOSE EVERY PROP.

Hitchcock was always known as a meticulous director obsessed with detail, but on Dial M for Murder he was particularly detail-oriented, in part because the 3D cameras were going to capture objects in a way his other films hadn’t. As a result, he selected all of the objects in the Wendice apartment himself, and even had a giant false telephone dial made for the famous “M” close-up in the title sequence.

7. KELLY’S WARDROBE GROWS DARKER ON PURPOSE.

Grace Kelly in 'Dial M for Murder' (1954)
Warner Home Video

Hitchcock’s exacting eye also led to an elaborate “color experiment” to portray the psychological condition of Kelly’s character. As the film begins, the colors she wears are all very bright, suggesting a happy life in which she doesn’t suspect anything is wrong. As the film grows darker for her, to the point that she’s framed for murder, the wardrobe grows darker and “more somber,” as Hitchcock put it.

8. KELLY WON A PARTICULAR WARDROBE ARGUMENT.

For the scene in which Swann (Anthony Dawson) attempts to murder Margot (Kelly) by strangling her (until she manages to stab him with a pair of scissors), Hitchcock had another exacting wardrobe request. He had an elegant velvet robe made for Kelly, hoping to create interesting textural effects as the lights and shadows played off the fabric while she fought for her life. Kelly reasoned that, since Margot was alone in the apartment (as far as she knew) and was only getting out of bed to answer the phone, she wouldn’t bother to put on a robe.

“I said I wouldn't put on anything at all, that I'd just get up and go to the phone in my nightgown. And [Hitchcock] admitted that was better, and that's the way it was done,” Kelly later recalled.

9. HITCHCOCK WAS SO NERVOUS ABOUT THE PIVOTAL SCENE THAT HE LOST WEIGHT.

Dial M for Murder was shot in just 36 days, but the director took special care with one scene in particular: the murder sequence in which Margot stabs Swann with the scissors. Not only was it a key scene in the film, but it was also a moment that required particular care to make the 3D effects work. Hitchcock agonized over the scene to such a degree that he apparently lost 20 pounds during filming.

"This is nicely done but there wasn't enough gleam to the scissors, and a murder without gleaming scissors is like asparagus without the hollandaise sauce—tasteless,” he reportedly said after one take.

10. HITCHCOCK MAKES HIS CAMEO IN A PHOTOGRAPH.

Hitchcock became known throughout his career for making cameos in his films, ranging from the very subtle (you can see his silhouette in neon outside the window in Rope) to the more elaborate (missing the bus in the opening sequence of North by Northwest). In Dial M for Murder, his cameo falls somewhere in between. He appears in a class reunion photo in the Wendice apartment, seated at a banquet table among other men.

11. IT’S BEEN REMADE FOUR TIMES.

Michael Douglas and Gwyneth Paltrow in 'A Perfect Murder' (1998)
Warner Bros.

Dial M for Murder was a film adaptation of a stage play that had also already been adapted for television in Britain, and it proved popular enough that four more adaptations followed. In 1958, NBC broadcast a Hallmark Hall of Fame production, in which both Anthony Dawson and John Williams returned to play Swann and Chief Inspector Hubbard, respectively. A 1967 ABC television production of the play co-starred Laurence Harvey and Diane Cilento. A television movie starring Angie Dickinson and Christopher Plummer was produced in 1981, and in 1998 the play served as the inspiration for the film A Perfect Murder, starring Michael Douglas and Gwyneth Paltrow.

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