Chapter 2 basic fingerprinting

• Before fingerprints became common, police needed a reliable way to identify repeat offenders.

• Early identification methods included photographs and physical descriptions, but these were not always dependable.

Alphonse Bertillon

• Alphonse Bertillon developed a system called Bertillonage.

• Bertillonage identified people using:

  • Body measurements

  • Physical descriptions

  • Photographs

• Measurements included parts of the body such as the head, arms, hands, and feet.

• The system worked because Bertillon believed adult body measurements stayed mostly unchanged.

Problems With Bertillonage

• Measurements could be affected by human error.

• Different officers could record measurements differently.

• Two people could have very similar physical measurements.

• The Will West/William West case showed the weaknesses of Bertillonage because the two men looked very similar and had nearly identical measurements but had different fingerprints.

Fingerprints

• Fingerprints eventually became a more reliable method of identification.

• Fingerprints are useful because ridge patterns are:

  • Permanent

  • Highly individual

  • Easy to classify and compare

Fingerprint Pattern Types

The main fingerprint patterns are:

• Arch

• Loop

• Whorl

Important features used in classification include:

• Core – approximate center of the fingerprint pattern.

• Delta – triangular area where ridge patterns separate.

Key Point to Remember

Bertillonage = body measurements and photographs
Major weakness = measurement errors and similar-looking people
Fingerprints replaced Bertillonage because they provide a more dependable method of personal identification.