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Inventors Police Technology and Forensic Science
By Mary Bellis

Police Cars
In 1899, the first police car was used in Akron, Ohio. Police cars became the basis of police transportation in the 20th century.

The Lie Detector/Polygraph - John Larson
John Larson, a University of California medical student, invented the modern lie detector (polygraph) in 1921. Used in police interrogation and investigation since 1924, the lie detector is still controversial among psychologists, and is not always judicially acceptable. The name polygraph comes from the fact that the machine records several different body responses simultaneously as the individual is questioned.

The theory is that when a person lies, the lying causes a certain amount of stress that produces changes in several involuntary physiological reactions. A series of different sensors are attached to the body, and as the polygraph measures changes in breathing, blood pressure, pulse and perspiration, pens record the data on graph paper. During a lie detector test, the operator asks a series of control questions that set the pattern of how an individual responds when giving true and false answers. Then the actual questions are asked, mixed in with filler questions. The examination lasts about 2 hours, after which the expert interprets the data.

An earlier and less successful lie detector or polygraph machine was invented by James Mackenzie in 1902. 

Police Technology
The history of the methods and techniques of police agencies and the equipment available to them. This is a long paper, with historical and technical information in different places.

The Bullet Proof Vest
The bullet proof vest was made possible by Stephanie Kwolek's invention of Kevlar, a material five times stronger than steel.

Bullet Proof Vests
Extracts from a National Institute of Justice Report - A History of Body Armor.

Forensic Science
Forensic science is a scientific method of gathering and examining evidence. Crimes are solved with the use of pathological examinations that gather fingerprints, palm prints, footprints, tooth bite prints, blood, hair and fiber samples. Handwriting and typewriting samples are studied, including all ink, paper, and typography. Ballistics techniques are used to identify weapons as well as voice identification techniques are used to identify criminals.

Italian, Fortunatus Fidelis, was the first person to practice modern forensic medicine in 1598. Forensic medicine is the "application of medical knowledge to legal questions." It became a recognized branch of medicine in the early 19th century.

In the 19th century it was observed that contact between someone's hands and a surface left barely visible and marks called fingerprints. Fine powder (dusting) was used to make the marks more visible.

Modern fingerprint identification dates from 1880, when the British scientific journal Nature published letters by the Englishmen Henry Faulds and William James Herschel describing the uniqueness and permanence of fingerprints. Their observations were verified by the English scientist Sir Francis Galton, who designed the first elementary system for classifying fingerprints based on grouping the patterns into arches, loops, and whorls. Galton's system was improved upon by London police commissioner, Sir Edward R. Henry. The Galton-Henry system of fingerprint classification, was published in June 1900, and officially introduced at Scotland Yard in 1901. It is the most widely used method of fingerprinting to date.

Sir Francis Galton
Biography of the English explorer, anthropologist, and eugenicist, who is known for his pioneering studies of human intelligence.

Forensic Science History
In 1248, a book, Hsi DuanYu (the Washing Away of Wrongs) published by the Chinese, described how to distinguish drowning from strangulation. It was the first recorded application of medical knowledge to the solution of crime.

Modern Forensics: Introduction
In recent years, the blend of science and technology has enabled police to solve many crimes that once would have been considered beyond resolution.

Forensic Sciences Guide
The basic principles of forensic science.

The History of Fingerprints
In 14th century Persia, various official government papers had fingerprints (impressions), and one government official, a doctor, observed that no two fingerprints were exactly alike.

A Brief History of Fingerprinting in the U.S.
The final step in bringing fingerprints to national prominence was the formation of the FBI Fingerprint Section under A. J. Renoe in 1924.

 It's the evidence left behind that is the true witness to crime. Forensic scientists convert these clues, using the latest technology into evidence admissible in a court of law.

Kids' Pages At The FBI
Crime busting information aimed at students.

Related Information
Fire Fighting Equipment
The first fire sprinkler system was invented by an American, Henry S. Parmalee, in 1874.

Firearms & Guns
The history of guns and firearms.

Home Security
The first home security system was patented (patent #3,482,037) on December 2, 1969.

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