The science of policing

As science has progressed, so has policing. Evidence collection, processing and analysis have grown more focused and exacting. Researchers have delved into the mysterious workings of the mind, found ground-breaking new ways to identify criminals and...


Not too long ago, new police recruits were told when to show up for work and assigned to a beat, often with little more than a few hours training. Most had to buy their own weapons and if evidence was collected at all, it was as an afterthought and with little accountability.

But as science progressed, so did policing. Evidence collection, processing and analysis grew more focused and exacting. Researchers delved into the mysterious workings of the mind, found ground-breaking new ways to identify criminals and victims and made the streets safer for the officers who patrolled them.

Join us below as LET celebrates a few of the many scientists whose works have contributed to the success of modern policing.

An accidental discovery continues to save lives

Chemist Stephanie Kwolek's curiosity and a willingness to see things through became a lifesaver for thousands of police officers, service members and firefighters the world over.

The young DuPont chemist had been experimenting in her research laboratory, searching for a new method in which to manufacture fibers and polymers (large molecules, which occur either synthetically or naturally, that are comprised of simple repetitive units). She and other researchers had been asked to find high-performance fibers that could reinforce rubber tires and make them more durable.

Kwolek's experiments led her to discover an odd opalescent substance that, she has said, most chemists would have discarded, but she thought there might be something to this new chemical compound she'd found. Kwolek asked that it be tested by another part of the lab, which specialized in spinning the liquids to measure, among other things, their strength and stiffness. Although rebuffed several times, Kwolek persisted until they spun the substance and the numbers were surprising. Kwolek retested the substance several times before taking her find to her bosses. Her discovery launched a new field of study in polymer chemistry.

The consumers that DuPont initially targeted—tire companies—weren't terribly interested in the new substance because using it meant they'd have to retrofit their production lines. However in 1971 DuPont introduced its find as Kevlar. Today, Kevlar has dozens of applications: It is used in bicycle tires and other sporting equipment, in musical instruments such as the reeds on woodwinds and as drumheads, to construct ropes, brakes, hoses, and even as a substitute for Teflon in some frying pans.

But its most significant application turned out to be as a component of protective gear for emergency responders. In addition to vests and gloves for police, Kevlar is also employed in turnout gear for firefighters and became widely used by the U.S. Armed Forces to make facemasks, helmets and armored vehicles.

Kevlar, which even its discoverer admits fought the odds to make it into production, ended up as the catalyst for saving the lives of countless men and women, both on battlefields as well as on the mean streets of the world's cities.

Identification right at their fingertips

Crime fighters had long been searching for an infallible method with which to identify criminals. In the 1870s, a French scientist named Alphonse Bertillon formulated a system for classifying habitual criminals by measuring certain human bones and keeping meticulous records of those measurements. The problem with Bertillon's system—which was used worldwide—was that it was cumbersome. Agencies that employed it had to keep extensive records and the measuring process itself was time intensive.

The Bertillon method remained in vogue for decades, but proved its fallibility in a case involving identical twins with the same aggregate bone measurements. The world's criminology community still lacked a foolproof method for determining criminals' identities until a British physician stepped up to the plate.

This content continues onto the next page...
301 Moved Permanently

Moved Permanently

The document has moved here.