Fingerprint Fundamentals Flashcards
What is a fingerprint?
A fingerprint is an impression left on a surface by the skin on the underside of the fingers and palms.
The skin on the undersides of our hands is different to the skin elsewhere on the body, as it is covered in rows and patterns of very small ridges. When we touch a surface, the sweat and oils on our hands is transferred to that surface, and under the right conditions, we will leave an impression which replicates the unique patterns of the skin.
Are fingerprints visible to the naked eye?
Fingerprints are most often invisible to the naked eye, therefore we use a range of methods to enhance and visualise them at the crime scene, and on exhibits in the forensic lab.
Are fingerprints always left on a surface when we touch it?
Fingerprints are not always left on a surface when we touch it, and this is because of the various factors, which relate to the person leaving the fingerprint, and the surface being touched, that determine whether or not a fingerprint is left on a surface when we tocuh it.
Fingerprints may not be left on a surface if there is no sweat or other residue on the skin at the time that the surface is touched, or if the surface is too textured or dirty for a fingerprint to be left. Alternatively, fingerprints are most likely to be left on smooth, clean surfaces.
