Police Technology and Forensic Science

Forensic Science
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Forensic science is a scientific method of gathering and examining the 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.

History of Forensic Science

The first recorded application of medical knowledge to the solution of crime was in the 1248 Chinese book Hsi DuanYu or the Washing Away of Wrongs, and it described ways to distinguish between death by drowning or death by strangulation.

Italian doctor, Fortunatus Fidelis is recognized as being the first person to practice modern forensic medicine, beginning 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.

The Lie Detector

An earlier and less successful lie detector or polygraph machine was invented by James Mackenzie in 1902. However, the modern polygraph machine was invented by John Larson in 1921.

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.


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.

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 first multi-shot pistol, introduced by Samuel Colt, goes into mass production. The weapon is adopted by the Texas Rangers and, thereafter, by police departments nationwide.

1854 to 59

San Francisco is the site of one of the earliest uses of systematic photography for criminal identification.


On June 17, 1862, inventor W. V. Adams patented handcuffs that used adjustable ratchets - the first modern handcuffs.


The use of the telegraph by fire and police departments begins in Albany, New York in 1877.


The telephone comes into use in police precinct houses in Washington, D.C.


Chicago is the first U.S. city to adopt the Bertillon system of identification. Alphonse Bertillon, a French criminologist, applies techniques of human body measurement used in anthropological classification to the identification of criminals. His system remains in vogue in North America and Europe until it is replaced at the turn of the century by the fingerprint method of identification.


Scotland Yard adopts a fingerprint classification system devised by Sir Edward Richard Henry. Subsequent fingerprint classification systems are generally extensions of Henry's system.


Edmund Locard establishes the first police department crime laboratory in Lyon, France.


The Los Angeles Police Department establishes the first police department crime laboratory in the United States.


The use of the teletype is inaugurated by the Pennsylvania State Police.


Detroit police begin using the one-way radio.


Boston Police begin using the two-way radio.


American police begin the widespread use of the automobile.


The prototype of the present-day polygraph is developed for use in police stations.


The FBI inaugurates its crime laboratory which, over the years, comes to be world-renowned.


Radar is introduced to traffic law enforcement.


The American Academy of Forensic Sciences (AAFS) meets for the first time.


The New Orleans Police Department installs an electronic data processing machine, possibly the first department in the country to do so. The machine is not a computer, but a vacuum-tube operated calculator with a punch-card sorter and collator. It summarizes arrests and warrants.


A former marine invents the side-handle baton, a baton with a handle attached at a 90-degree angle near the gripping end. Its versatility and effectiveness eventually make the side-handle baton standard issue in many U.S. police agencies.

  • Introduction: What is Forensic Science & History?
  • Polygraph Machines
  • Other Equipment: Fingerprinting, Police Cars
  • Timeline of Police Technology 1850 - 1960, 1960 - 1996