At a. The police arrived and did something that is increasingly a part of everyday crime fighting: They swabbed the crime scene for DNA. Normally, you might think of DNA as the province solely of high-profile crimes—like murder investigations, where a single hair or drop of blood cracks a devilish case.
Nope: These days, even local cops are wielding it to solve ho-hum burglaries. They had their suspect. When it first appeared over 30 years ago, it was an arcane technique.
Yet the DNA revolution has unsettling implications for privacy. After all, you can leave DNA on everything you touch—which means, sure, crimes can be more easily busted, but the government can also more easily track you.
In , the scientist J. It was an interesting observation, but one that lay dormant until 19th-century society began to grapple with an emerging problem: How do you prove people are who they say they are? Carrying government-issued identification was not yet routine, as Colin Beavan, author of Fingerprints , writes. Cities like London were booming, becoming crammed full of strangers—and packed full of crime.
The sheer sprawl of the population hindered the ability of police to do their work because unless they recognized criminals by sight, they had few reliable ways of verifying identities. A first-time offender would get a light punishment; a habitual criminal would get a much stiffer jail sentence. But how could the police verify whether a perpetrator they hauled in had ever been caught previously?
Faced with this problem, police tried various strategies for identification. Photographic mug shots helped, but they were painstakingly slow to search through. In the s, a French police official named Alphonse Bertillon created a system for recording 11 body measurements of a suspect, but it was difficult to do so accurately. The idea of fingerprints gradually dawned on several different thinkers.
One was Henry Faulds, a Scottish physician who was working as a missionary in Japan in the s. He began inking prints of his colleagues at the hospital—and noticing they seemed unique.
Faulds even used prints to solve a small crime. An employee was stealing alcohol from the hospital and drinking it in a beaker.
How reliable were prints, though? Together, they mold the direction of the growing ridges. Koalas and chimpanzees have unique fingerprints, too. Like humans, their hands and feet are covered in friction ridges. That might mean friction ridges give texture to grab rough or slippery things. Some scientists think cats might have unique noseprints. Search for:. Videos Activities Podcasts. Even identical twins — who have the same DNA sequence and tend to share a very similar appearance — have slightly different fingerprints.
Fingerprints are set between 13 and 19 weeks of foetal development. The precise details of the whorls, ridges, and loops are affected by many factors, including umbilical cord length, position in the womb, blood pressure, nutrition and the rate of finger growth.
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