Bell Work What crime did he commit? What forensic evidence led to his conviction? Read the Case Study on James Earl Ray on page 470 in your textbook

History and Fundamental Principles of Fingerprints Chapter 14 History and Fundamental Principles of Fingerprints

Fingerprints Although fingerprint ID is now standard practice, acceptance of the individuality of FP by police, scientists, and the courts didn’t happen overnight. In the US, the first systematic and official use of FP for personal ID was adopted by the NYC Civil Service Commission in 1901.

History of Fingerprints The Chinese used fingerprints to sign legal document as much as 3,000 years ago William Herschel, and English civil servant, required natives in India to sign contracts with the imprint of their right hand in the 1800’s In 1880 Henry Fauld published a book suggesting skin ridge patterns could be used for identification The Bertillon system of anthropometry was commonly used

Early Classification of Fingerprints Englishman, Francis Galton, published a book in 1892 entitled Finger Prints which stated that fingerprints can be grouped into loops, arches, and whorls. The British government adopted using fingerprints in addition to the Bertillion system

The West Case For many years, scientists used a system called the Bertillon System (which records the dimensions of certain skeletal body parts) to ID. But in 1903, Leavenworth Federal Penitentiary received a prisoner by the name of Will West. Will had almost the same Bertillon measurements as another prisoner serving a life sentence for murder.

The 2 unrelated criminals also looked identical, had similar names, but their fingerprints were different. It was practically the ONLY way they could distinguish the 2 prisoners. Thanks to this case, fingerprinting became the standard for personal ID.

Fundamental Principles The usefulness of fingerprints for identification depends upon 3 principles Ridge characteristics are unique patterns created by friction ridges and sweat pores The identity, number, and location of characteristics are used to identify individuals A point-by-point comparison can determine if the nearly 150 individual ridge characteristics are the same on prints

1st Principle A fingerprint is individual and is not shared by any two people Galton’s original book refers to 64 billion different possibilities The FBI has 50 million fingerprint records … all unique. They are kept in the AFIS system

2nd Principle A fingerprint remains unchanged throughout life Skin is made of layers of cells (epidermis and dermis) Skin ridge patterns develop before birth and consist of pores and ducts from sweat glands Perspiration and oils transfer when you touch something Latent prints consist of oil deposits which are invisible to the naked eye Scaring can’t obscure all characters but create new identifying marks

3rd Principle 65% of the population have loops 30-35% have whorls 5% have arches Fingerprints exhibit general patterns that provide a basis for classification The 3 classes of fingerprints are loops, whorls, and arches

Case Study Read the Case Study in your lab manual on page 32 Who was the “Night Stalker” and what crimes did he commit? What forensic evidence was used to convict the Night Stalker?