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The Prints Match Those of ...
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The Prints Match Those of ...

Credit: Pearson Scott Foresman
Source: http://commons.wikimedia.org/wiki/File:Fingerprint_(PSF).png
License: CC BY-NC 3.0

Fingerprints are unique identifiers for all humans. No two individuals have identical prints. The use of fingerprints for identification dates back over 2000 years. Until recently, these prints were detected using chemical techniques. New methods explore sophisticated devices that are much more sensitive.

News You Can Use

  • A number of chemical approaches to detection of fingerprints have been used for decades. These techniques differ in sensitivity and reliability. Many of the approaches are messy and damaging to the underlying material.
  • Dusting for fingerprints involves the use of carbon or aluminum powder. The residue from these powders can often be difficult to clean up. Other chemical can be used in specific situations, but the print is usually useless for further analysis after these chemical treatments.
  • A new technique, called micro-X-ray fluorescence (MXRF) is being studied for fingerprint detection. Salts such as sodium and potassium chlorides will fluoresce when radiated by the device and can be detected easily. The new technique does not require chemical treatment of the surface and is non-destructive.
  • Fingerprints can be detected on a number of surfaces that are difficult to study using other approaches. The print can later be analyzed by other means, including DNA analysis.
  • Fingerprints scanners can also check for identity. They are used in computers and mobile phones to allow the owner to use the device without cumbersome passwords. 
  • Credit: SparkFun Electronics
    Source: http://www.flickr.com/photos/sparkfun/9145205744/
    License: CC BY-NC 3.0

    A fingerprint scanner that's small enough to be used in a mobile phone [Figure2]

     

  • Watch the video at the link below to learn more about fingerprints and their detection:

http://www.youtube.com/watch?v=Ry8920R7bxs

Show What You Know

With the links below, learn more about fingerprint detection. Then answer the following questions.

  1. How many fingerprints are in the INTERPOL file of prints on important international criminals? How many prints are on file with the FBI?
  2. What are latent prints?
  3. What is Amido Black?
  4. Why are children’s prints often difficult to detect?

Image Attributions

  1. [1]^ Credit: Pearson Scott Foresman; Source: http://commons.wikimedia.org/wiki/File:Fingerprint_(PSF).png; License: CC BY-NC 3.0
  2. [2]^ Credit: SparkFun Electronics; Source: http://www.flickr.com/photos/sparkfun/9145205744/; License: CC BY-NC 3.0

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